oxide tft lcd made in china

LCD manufacturers are mainly located in China, Taiwan, Korea, Japan. Almost all the lcd or TFT manufacturers have built or moved their lcd plants to China on the past decades. Top TFT lcd and oled display manufactuers including BOE, COST, Tianma, IVO from China mainland, and Innolux, AUO from Tianwan, but they have established factories in China mainland as well, and other small-middium sizes lcd manufacturers in China.

China flat display revenue has reached to Sixty billion US Dollars from 2020. there are 35 tft lcd lines (higher than 6 generation lines) in China,China is the best place for seeking the lcd manufacturers.

The first half of 2021, BOE revenue has been reached to twenty billion US dollars, increased more than 90% than thesame time of 2020, the main revenue is from TFT LCD, AMoled. BOE flexible amoled screens" output have been reach to 25KK pcs at the first half of 2021.the new display group Micro LED revenue has been increased to 0.25% of the total revenue as well.

Established in 1993 BOE Technology Group Co. Ltd. is the top1 tft lcd manufacturers in China, headquarter in Beijing, China, BOE has 4 lines of G6 AMOLED production lines that can make flexible OLED, BOE is the authorized screen supplier of Apple, Huawei, Xiaomi, etc,the first G10.5 TFT line is made in BOE.BOE main products is in large sizes of tft lcd panel,the maximum lcd sizes what BOE made is up to 110 inch tft panel, 8k resolution. BOE is the bigger supplier for flexible AM OLED in China.

Technology Co., Ltd), established in 2009. CSOT is the company from TCL, CSOT has eight tft LCD panel plants, four tft lcd modules plants in Shenzhen, Wuhan, Huizhou, Suzhou, Guangzhou and in India. CSOTproviding panels and modules for TV and mobile

three decades.Tianma is the leader of small to medium size displays in technologyin China. Tianma have the tft panel factories in Shenzhen, Shanhai, Chendu, Xiamen city, Tianma"s Shenzhen factory could make the monochrome lcd panel and LCD module, TFT LCD module, TFT touch screen module. Tianma is top 1 manufactures in Automotive display screen and LTPS TFT panel.

Tianma and BOE are the top grade lcd manufacturers in China, because they are big lcd manufacturers, their minimum order quantity would be reached 30k pcs MOQ for small sizes lcd panel. price is also top grade, it might be more expensive 50%~80% than the market price.

Panda electronics is established in 1936, located in Nanjing, Jiangshu, China. Panda has a G6 and G8.6 TFT panel lines (bought from Sharp). The TFT panel technologies are mainly from Sharp, but its technology is not compliance to the other tft panels from other tft manufactures, it lead to the capacity efficiency is lower than other tft panel manufacturers. the latest news in 2022, Panda might be bougt to BOE in this year.

Established in 2005, IVO is located in Kunsan,Jiangshu province, China, IVO have more than 3000 employee, 400 R&D employee, IVO have a G-5 tft panel production line, IVO products are including tft panel for notebook, automotive display, smart phone screen. 60% of IVO tft panel is for notebook application (TOP 6 in the worldwide), 23% for smart phone, 11% for automotive.

Besides the lcd manufacturers from China mainland,inGreater China region,there are other lcd manufacturers in Taiwan,even they started from Taiwan, they all have built the lcd plants in China mainland as well,let"s see the lcd manufacturers in Taiwan:

Innolux"s 14 plants in Taiwan possess a complete range of 3.5G, 4G, 4.5G, 5G, 6G, 7.5G, and 8.5G-8.6G production line in Taiwan and China mainland, offering a full range of large/medium/small LCD panels and touch-control screens.including 4K2K ultra-high resolution, 3D naked eye, IGZO, LTPS, AMOLED, OLED, and touch-control solutions,full range of TFT LCD panel modules and touch panels, including TV panels, desktop monitors, notebook computer panels, small and medium-sized panels, and medical and automotive panels.

AUO is the tft lcd panel manufacturers in Taiwan,AUO has the lcd factories in Tianma and China mainland,AUOOffer the full range of display products with industry-leading display technology,such as 8K4K resolution TFT lcd panel, wide color gamut, high dynamic range, mini LED backlight, ultra high refresh rate, ultra high brightness and low power consumption. AUO is also actively developing curved, super slim, bezel-less, extreme narrow bezel and free-form technologies that boast aesthetic beauty in terms of design.Micro LED, flexible and foldable AMOLED, and fingerprint sensing technologies were also developed for people to enjoy a new smart living experience.

Hannstar was found in 1998 in Taiwan, Hannstar display hasG5.3 TFT-LCD factory in Tainan and the Nanjing LCM/Touch factories, providing various products and focus on the vertical integration of industrial resources, creating new products for future applications and business models.

driver, backlight etc ,then make it to tft lcd module. so its price is also more expensive than many other lcd module manufacturers in China mainland.

Maclight is a China based display company, located in Shenzhen, China. ISO9001 certified, as a company that more than 10 years working experiences in display, Maclight has the good relationship with top tft panel manufacturers, it guarantee that we could provide a long term stable supply in our products, we commit our products with reliable quality and competitive prices.

Maclight products included monochrome lcd, TFT lcd module and OLED display, touch screen module, Maclight is special in custom lcd display, Sunlight readable tft lcd module, tft lcd with capacitive touch screen. Maclight is the leader of round lcd display. Maclight is also the long term supplier for many lcd companies in USA and Europe.

If you want tobuy lcd moduleorbuy tft screenfrom China with good quality and competitive price, Maclight would be a best choice for your glowing business.

Oxide (Oxide semiconductor) TFT display, which its strengths are low-power design and miniaturization, is rapidly expanding its influence in market. As Apple is planning to release iPad Pro that has Oxide TFT Panel soon, it seems that it will make a sudden rise as next generation panel along with Low-Temperature Poly Silicon (LTPS) TFT.

According to industry, Korean and foreign display industries are currently expanding production capabilities of Oxide TFT Panels that are boards for premium displays. They are planning to either change parts of previous amorphous-Silicon (a-Si) TFT LCD’s production lines to Oxide lines or extend them.

Because Oxide TFT Panels have faster electron traveling speed than previous a-Si TFT LCD, low-powered design is possible and battery efficiency can be maximized. Because its thickness can also be reduced up to 30% compared to previous panels, it is favorable to make finished products slimmer. It is first applied to medium and small-sized tablet PCs that can maximize its strengths.

Apple first brought this trend of changes in technologies. Apple will first apply Oxide TFT panels onto its iPad Pro that will be released in September and it is planning to apply Oxide TFT panels onto other products such as iMac and iPad and others hereafter. Korean and foreign display businesses are increasing their outputs according to this flow.

Samsung Display is currently changing its Cheonan Gen 5 (1100x1300mm) L6 Line to Oxide Line and is planning to expand its size to 100,000 sheets per month by next year from current 40,000 sheets per month. LG Display is also remodeling and expanding Oxide Lines at Paju Gen 8 P8 and P9 lines.

China is also planning to join trend. Chinese businesses such as BOE, CEC-Panda, and CSOT that are currently operating Pilot Lines are going into full-scale mass-production starting from this year. Chinese government is planning to expand output of LTPS and Oxide TFT-based LCDs by 5 million m2 per year.

Forecast of equipment industry is also very bright. Process of crystallizing through heat treatment at hundreds of degrees is a must for Oxide TFT process. Demand for this process was low for previous a-Si TFT, and Viatron and Terasemicon in Korea have unrivaled technologies in this area. As market demand is planning to be increased, many equipment businesses are preparing to enter into market for heat treatment equipment.

“Although there are a lot of difficulties in securing yields because Oxide TFT is sensitive to outside environment due to organic substances, it is at a condition where most of technology process is achieved. It will soon form 2 prominent technologies with LTPS boards as next generation board technologies.” said a person in this industry.

Scientists as the University of Manchester and Shandong University in China havedeveloped an ultrafast, thin film transistor (TFT) made out of the metal oxide semiconductor InGaZnO. The TFT is claimed to be first oxide-semiconductor based transistor capable of operating at a benchmark speed of 1 GHz. Using such TFTs could help to make next generation screens faster, brighter and more flexible, according to the researchers.

TFTs are mainly used in LCD screens to rapidly switch each individual pixel on and off. Most current TFTs are silicon-based and as such are opaque and rigid in comparison to the oxide semiconductor family of transistors which the team from the UK and China is developing. Whilst oxide TFTs will improve picture quality on LCD displays, it is their flexibility that is even more impressive, saysAimin Song, professor of Nanoelectronics in the School of Electrical & Electronic Engineering, the University of Manchester.

"TVs can already be made extremely thin and bright. Our work may help make TVs more mechanically flexible and even cheaper to produce.But, perhaps even more importantly, our GHz transistors may enable medium or even high performance flexible electronic circuits, such as truly wearable electronics. Wearable electronics requires flexibility and in many cases transparency, too. This would be the perfect application for our research.Plus, there is a trend in developing smart homes, smart hospitals and smart cities - in all of which oxide semiconductor TFTs will play a key role," he explains.

Metal oxide-based semiconductor technology has seen rapid development when compared to its silicon counterpart which is increasingly close to some fundamental limitations. Song says there has been fast progress in oxide-semiconductors in recent years and extensive efforts have been made in order to improve the speed of oxide-semiconductor-based TFTs.

So much so some oxide-based technology has already started replacing amorphous silicon in some gadgets. Song thinks these latest developments have brought commercialisation much closer.

He added: "To commercialise oxide-based electronics there is still a range of research and development that has to be carried out on materials, lithography, device design, testing, and last but not the least, large-area manufacturing. It took many decades for silicon technology to get this far, and oxides are progressing at a much faster pace.

"Making a high performance device, like our GHz IGZO transistor, is challenging because not only do materials need to be optimised, a range of issues regarding device design, fabrication and tests also have to be investigated. In 2015, we were able to demonstrate the fastest flexible diodes using oxide semiconductors, reaching 6.3 GHz, and it is still the world record to date. So we"re confident in oxide-semiconductor based technologies. "

Samsung Display, one of the leading amorphous silicon (a-Si) TFT LCD manufacturers for the past 20 years, is shutting down its first G7 line, Line 7-1, from as early as the end of July and there are rumors of a few more fab closures to come. Its a-Si TFT LCD footprint is expected to shrink dramatically over the next few years with potentially just one a-Si fab in operation in 2018 to serve its market-leading TV business.

Panasonic LCD is also rumored to be shutting down most or all of its G8.5 line. Based on the near term decline in a-Si TFT LCD capacity, Credit Suisse upgraded AUO and Innolux on this news and their shares surged.

Samsung’s Line 7-1, which began operation in October 2004 and production in May 2005, is rumored to be shutting down from the 30th July through the end of the year. It has a unique glass size (1,870 x 2,200mm), which was the largest in the world at the time of its introduction and is optimized for both 40” and 46” LCD TV panel production. It was also the site of the Samsung-Sony joint venture, S-LCD, established in April 2004. This line enabled Samsung and Sony to rapidly take share from smaller G6 fabs optimized for 32” and 37” panels. During that time, the two companies competed aggressively in retail while establishing 40” and 46” as mainstream sizes. The JV with Sony ended in 2011. S-LCD also built an 8th gen fab that began production in Q3’07, and Samsung built a second G7 line (L7-2) on its own, with even more capacity at over 170,000 substrates per month. L7-2 began production in Q3’08.

Displays are already a weak spot in Samsung’s financial performance. The category caused the device solutions division to be the only one to suffer a loss among all major divisions within Samsung in Q1’16, and its revenues of KRW6 trillion ($5.2 billion) were the lowest in two years. The display division alone posted an operating loss of KRW270 billion ($233 million) in Q1’16 resulting in an operating margin of -4.4%. While Samsung has a number of technology and capacity advantages in OLEDs for mobile displays, its a-Si TFT LCD business has matured and is increasingly becoming commoditized, as new entrants from China with government support are taking share. In addition, most of the a-Si TFT LCD market segments have become stagnant or are in decline, which points to more losses given the growing Chinese competition. On the other hand, OLEDs and flexible OLEDs are poised for rapid growth as they take share. As a result, it makes good business sense for Samsung to exit much of the a-Si TFT LCD market.

That is not all, however. Line 6, Samsung"s last 5th gen line with 1,100 x 1,300mm substrates and around 190,000 substrate per month capacity, is also expected to be shut down, according to industry insiders. That line, which features a-Si and oxide TFT LCD production, has been producing tablet, notebook PC and LCD monitor panels. Those markets have also been hit by stagnant demand, growing competition from China, commoditization and declining margins. This line is expected to be shut down between the end of 2016 and 2017. Line 6 is predicted to be converted to a semiconductor facility, making application processors for smartphones and tablets.

If Samsung closes down Line 6 and Lines 7-1 and 7-2, its a-Si production will be down to just two G8.5 fabs: one in Suzhou, China and one in Tangjong, Korea. The Suzhou fab, ramping to over 100,000 substrates per month, is also rumored to be a candidate for sale with Chinese and Indian TFT LCD suppliers as potential customers. If Samsung licenses its latest a-Si TFT LCD or oxide TFT LCD technology, that would certainly make the sale more attractive. This means Samsung would have just one a-Si TFT LCD fab: Line 8.

I believe Line 8 will be sufficient for Samsung to support its internal TV brand with leading edge panels for the TV market as it has a monthly capacity of 400,000 2,200 x 2,500mm (G8.5) substrates. Samsung’s TV business would likely continue to outsource its low-end panels for its TVs to other LCD manufacturers and focus this fab on higher margin products such as 8k, HDR, QD WCG, etc. I cannot see Samsung abandoning LCD TV panel production until it believes OLEDs are cost effective enough to takeover the mid-range high end of the TV market. This likely means not until OLED materials can be inkjet printed, Samsung is still likely to focus all of its TV panel production on LCDs.

If this occurs as described, Samsung Display"s output of 42" and larger panels would be LCD, and sub-42" would be OLED, although it may not have much production between 15" and 40". This would be an amazing, but expected, transformation given the supply/demand and profitability outlook for the a-Si market.

2016 and 2017 are expected to be back-to-back years of over $12 billion in LCD/OLED equipment spending. Unless these fabs struggle with their ramp and their yields, the a-Si market will continue to be oversupplied although conditions should improve in the 40”-43” market in the second half of 2016.

Rather than battle it out with government-subsidized Chinese players, Samsung appears to be accelerating its exit of the increasingly commoditized a-Si TFT LCD market. This should please its shareholders, especially if it can sell all its old equipment and license its a-Si technology for a royalty, but will be harmful to some of its suppliers. It is also likely to protect its TV business by holding onto its most competitive fab, but will increasingly become an OLED company. Interesting questions as a result of these moves include:

A couple of days after this article was originally posted, it was claimed - and later denied by a company official - that Samsung will move its a-Si TFT LCD operations out of Samsung Display and into Samsung Electronics. Such a move aligns perfectly with its intention, indicated above, to close its a-Si fabs as in a couple of years its a-Si TFT LCD operations may be limited to providing panels to its TV business. - Ross Young

Ross Young is the CEO and Founder of Display Supply Chain Consultants. He also serves on the Board of Directors of publicly traded touch sensor manufacturer UniPixel and diamond semiconductor developer Akhan Technologies. He previously founded DisplaySearch and served as its CEO from 1996 - 2007 where he launched most of their categories of coverage. He has also held executive positions at Samsung LCD and IMS Research.

4.5.Comparing the key attributes of different TFT technologies (a-Si, pc-Si, nc-Si, OTFT, graphene, CNT, etc). Parameters include manufacturing technique, mobility, uniformity, stability, and commercialisation stage and primary uses

7.1.Radar chart assessing the merits of different backplane technologies (LTPS, oxide, a-Si, organics) for LCD displays. The parameters considered are resolution, size, flexibility, on-pixel processing, and 3D. Here, the scale is from

7.2.Radar chart assessing the merits of different backplane technologies (LTPS, oxide, a-Si, organics) for OLED displays. The parameters considered are resolution, size, flexibility, on-pixel processing, and 3D. Here, the scale is fro

7.7.Announced annual production capacity (area) of various OLED display manufactures in 2015-2016. Two categories are developed: 1) LTPS backplanes and 2) oxide backplanes

China"s first 8.5-generation TFT-LCD production line was launched in Bengbu, East China"s Anhui province, on June 18, 2019, representing a breakthrough in the production of high-definition LCD screen, Science and Technology Daily reported.

TFT-LCD, or Thin Film Transistor Liquid Crystal Display, is key strategic material of the electronic information display industry. The Gen 8.5 TFT-LCD production line, launched by the Bengbu Glass Industry Design and Research Institute of the China National Building Material Group, will produce high-definition LCD screens of 55 inches, the report said.

According to the Liquid Crystal Branch of the China Optics and Optoelectronics Manufactures Association, the demand for TFT-LCD in the Chinese mainland was about 260 million square meters in 2018, including 233 million square meters" Gen 8.5 TFT-LCD. However, the annual supply of domestically made TFT-LCD is less than 40 million square meters, with all of them Gen 6 or below, which cannot meet the demand in scale and quantity.

The association predicted that China"s market demand for Gen 8.5 TFT-LCD or above will exceed 300 million square meters by 2020, accounting for 49.6 percent of the total global demand.

The production and control precision of Gen 8.5 TFT-LCD is comparable to that of the semiconductor industry, representing a higher level of large-scale manufacturing of modern glass industry.

The institute in Bengbu, with 60 years of expertise in glass, has finally made a breakthrough in the production of Gen 8.5 TFT-LCD, and will provide key raw material guarantee for China"s LCD panel industry after it goes into mass production in September, the report said.

The low–temperature poly–Si oxide (LTPO) backplane is realized by monolithically integrating low–temperature poly–Si (LTPS) and amorphous oxide semiconductor (AOS) thin–film transistors (TFTs) in the same display backplane. The LTPO–enabled dynamic refreshing rate can significantly reduce the display’s power consumption. However, the essential hydrogenation of LTPS would seriously deteriorate AOS TFTs by increasing the population of channel defects and carriers. Hydrogen (H) diffusion barriers were comparatively investigated to reduce the H content in amorphous indium–gallium–zinc oxide (a–IGZO). Moreover, the intrinsic H–resistance of a–IGZO was impressively enhanced by plasma treatments, such as fluorine and nitrous oxide. Enabled by the suppressed H conflict, a novel AOS/LTPS integration structure was tested by directly stacking the H–resistant a–IGZO on poly–Si TFT, dubbed metal–oxide–on–Si (MOOS). The noticeably shrunken layout footprint could support much higher resolution and pixel density for next–generation displays, especially AR and VR displays. Compared to the conventional LTPO circuits, the more compact MOOS circuits exhibited similar characteristics.

Keywords:low–temperature poly–Si oxide (LTPO), amorphous indium–gallium–zinc oxide (a–IGZO), thin–film transistors (TFT), diffusion barrier, hydrogen–resistant, nitrous oxide (N2O), fluorination, metal–oxide–on–Si (MOOS)

As the amorphous silicon thin–film transistors (TFTs) cannot meet the elevated requirements of active–matrix displays on higher resolution, the lower power consumption, and higher flexibility, the low–temperature fabrication, the ultralow off–state current (Ioff), and other superiorities of AOS TFTs [1,2] have attracted attention in the rapidly growing field of research in in display [3] and flexible electronics [4]. The amorphous indium–gallium–zinc oxide (a–IGZO) TFT [5] is evidence of progress in this field. However, AOS TFTs exhibited relatively lower mobility and poorer stability compared to low–temperature poly–Si (LTPS) TFTs, restricting their applications to high–end displays and other cutting–edge electronic systems. To combine the metrics of both LTPS and AOS, the low–temperature poly–Si oxide (LTPO) technology was tested by monolithically integrating LTPS and AOS TFTs. This technology enables a dynamic refresh rate and, thus, considerably reduces power consumption [6]. Unfortunately, as the hydrogen (H) doping is essential for passivating the dangling bonds in LTPS [7], the AOS TFTs would be severely degraded by these H dopants diffused from the LTPS TFTs, due to the abundant generation of defects and donors in the AOS channels [8]. Thus, it is imperative for the further improvement of LTPO systems to suppress the detrimental H–influence on AOS TFTs [9,10].

As shown in Figure 1a, the a–IGZO TFTs were fabricated in the self–aligned top–gate (SATG) architecture; this procedure followed our previously reported process [11,14]. The H–blocking capabilities of passivation layers (PL) were compared to different passivation–layer materials. The controlled passivation layer was 200–nm–thick silicon oxide (SiO2) deposited using the plasma–enhanced chemical vapor deposition (PECVD) with silane (SiH4) and nitrous oxide (N2O) as the reactive gases. Another passivation layer of 200–nm–thick AlOX was reactively sputtered in the argon–O2 mixed ambience; the aluminum (Al) target was used for this procedure. On top of the PECVD–SiO2 passivation layer, a 5–nm sputtered Al film was fully oxidized in O2 at 200 °C for 30 s, forming the SiO2/Oxidized–AlOX bilayer. The hydrogenation treatment of these a–IGZO TFTs was implemented by capping these a–IGZO TFTs with H–rich PECVD silicon nitride (SiNX:H) deposited with the SiH4 and ammonia (NH3). These SATG a–IGZO TFTs with a different passivation layer were characterized with the B1500A Semiconductor Parameter Analyzer semiconductor analyzer, before and after the hydrogenation process.

(a) The schematic cross–section of the SATG IGZO TFT with hydrogenation capping layer. Transfer characteristics of a–IGZO TFTs with (b) PECVD SiO2 passivation layer, (c) sputtered–AlOX passivation layer, and (d) SiO2/Oxidized–AlOX passivation layer before and after the hydrogenation.

The drain current (IDS) versus gate voltage (VGS) transfer curves of transistors with both a channel width (W) and a length (L) of 100 μm were measured at a drain voltage (VDS) of 10.1 V. The threshold voltage (Vth) was extracted as the VGS corresponding to an L/W-normalized IDS of 10−6 A. In Figure 1b, the Vth of the SiO2–passivated a–IGZO TFT was 0.5 V before the hydrogenation and severely degraded to −28.5 V after the hydrogenation, a result suggesting that abundant H dopants diffuse through the SiO2 passivation layer into a–IGZO channel [18]. The TFTs with a sputtered–AlOX passivation layer were short–circuited by the hydrogenation (Figure 1c), while the extracted Vth of the SiO2/AlOX–passivated TFT only shifted to −11 V (Figure 1d). The results indicated that the film compactness of sputtered AlOX was even worse than that of PECVD SiO2, leading to the heavily H–doped conductive channel. With the addition of only 5–nm thermally–oxidized AlOX, the SiO2/oxidized–AlOX bilayer exhibited much better H–blocking capability than the SiO2 single layer. However, the ultrathin thermally–oxidized AlOX cannot completely block the H diffusion, due to the self–limited nature of Al oxidization. Therefore, it is necessary to elevate the intrinsic H–resistance of AOS TFTs against the residual H dopants penetrating through the bilayer passivation layer.

The H–resistance of SiO2–passivated AOS TFTs was further investigated by additionally treating the a–IGZO islands with N2O plasma at 150 °C. In Figure 2a,b, the H–effects were compared on the a–IGZO TFTs with different N2O treatment times. As shown in Figure 1b, the untreated a–IGZO TFTs were seriously degraded by hydrogenation. The nearly shorted channel is caused by the numerous H dopants that penetrate the SiO2 passivation layer and diffuse into a–IGZO. For the same L of 100 μm, the H–induced ΔVth (Vth before and after the hydrogenation) was significantly decreased to −11.4 V by the 60–s N2O treatment, as shown in Figure 2a. This suggests that the H–resistance of the N2O–treated a–IGZO channel was effectively strengthened. However, the ΔVth of 20–μm–L TFT shifted to −12.7 V, and the 5–μm–L channel was still shorted. Such an apparent short–channel effect (SCE) reveals that the channel–carrier concentration is gradually increased by the lateral H diffusion; this evidence is consistent with the perfect H–blocking capability of the top metal gate [19].

When the N2O treatment was prolonged to 360 s (Figure 2b), the Vth of long–channel TFTs exhibited almost no degradation after the hydrogenation, while the ΔVth of 5–μm–L TFT only slightly shifted to −3.6 V, revealing a significantly strengthened H–resistance of such strongly oxidized a–IGZO. However, the on–state current (Ion) of such strongly oxidized a–IGZO TFT was degraded after the hydrogenation, especially for the 5–μm–L transistor, a result suggesting a significantly increased source/drain (S/D) resistance (RSD). Most plausibly, although the resistivity of strongly oxidized a–IGZO can still be effectively reduced by the argon plasma–induced donor defects [17,20], the additional H dopants suppress these donor defects rather than further supply donors; this process could result in an elevated RSD. As illustrated in Figure 1a, the LSD is even longer for the shorter–L transistor, causing an even larger RSD and thus seriously limiting the Ion of 5–μm–L TFT (Figure 2b).

The fluorination can also effectively passivate the O– and H–related defects in AOS [23,24]; thus, it was combined with the N2O plasma in this work. The as–deposited a–IGZO was first immersed in the carbon tetrafluoride (CF4) plasma at 150 °C for 600 s to form the fluorinated a–IGZO (a–IGZO:F) and then treated with the N2O plasma for 360 s in the same PECVD reactor. As shown in Figure 4a, the key parameters of N2O–treated a–IGZO:F TFTs were well maintained after the hydrogenation, including the field–effect mobility (μFE), subthreshold slope (SS), and on/off ratio (Figure 4b). Even for 5–μm–L TFT, the ΔVth only slightly degraded by less than −1.5 V. In addition, the RSD after the hydrogenation of a–IGZO is 185.1 kΩ/sq, and a–IGZO:F is 110.0 kΩ/sq, which is reduced by 40%, a reduction that improves the serious degradation of Ion. The metal fluorine (M–F) bonds formed during the fluorination process have much higher dissociation energies than the counterpart M–O bond [25], as listed in the Inset. Therefore, the combination of fluorination and oxidization furthest suppresses the native defects in a–IGZO and thus effectively enhances the H–resistant capability of a–IGZO TFTs.

(a) The transfer characteristics of 360–s N2O–treated a–IGZO:F TFTs and (b) corresponding key parameters before and after the hydrogenation of the 5–μm–L a–IGZO:F TFTs.

The successful development of H–resistant AOS TFT blazes a new trail for LTPO architecture. Distinct from the conventional side–by–side LTPO structure [26], a 3D integration structure of LTPS and a–IGZO TFTs, dubbed metal–oxide–on–Si (MOOS) architecture, was proposed; the demonstration of a basic inverter circuit supported this proposal. The H–resistant a–IGZO:F TFT was also fabricated in the bottom–gate elevated–metal metal–oxide (EMMO) structure [16] and then integrated with the solid–phase–crystallized (SPC) LTPS TFT [27]. The source/drain (S/D) activation of n+ a–IGZO and p+ LTPS was implemented with the same O2 annealing process at 500 °C for 4 h. Distinct from the existing side–by–side LTPO structure [26], a 3D integration structure of LTPS and a–IGZO TFTs was proposed, and this proposal was supported by the demonstration of an inverter circuit module, dubbed metal–oxide–on–Si (MOOS) architecture. As shown in Figure 5a, the CMOS inverter built in the mainstream planar LTPO structure occupies a large footprint and thus cannot meet the increasing demands on high–resolution high–PPI display. The MOOS invertor exhibited a superior layout efficiency by saving nearly 16% area. However, the compact integration of a–IGZO and LTPS TFTs demands a strong H–immunity of IGZO transistor.

In Figure 6a, the full–swing CMOS inverters were successfully demonstrated by integrating the n–type a–IGZO:F TFT and the p–type poly–Si TFT. In light of the process flow of LTPS TFT, only one more photolithography mask of AOS island is added for realizing a compact CMOS circuit, while the traditional CMOS poly–Si circuits require at least two more masks than PMOS poly–Si circuits. Due to the absence of high–performance p–type AOS, the AOS inverters are normally made of unipolar AOS and thus hardly achieve the full swing, or the number of transistors has to be doubled to realize the pseudo–CMOS circuits [28]. The low–cost CMOS circuits can be achieved by hybrid integrating AOS and LTPS, and the integration density can be further enhanced by using the MOOS structure.

In this work, a–IGZO TFTs with different passivation layers were comparatively subjected to hydrogenation, and the results recommended the PECVD SiO2/thermally–oxidized AlOX bilayer as the H–blocking candidate. The combination of N2O pretreatment and fluorine doping was developed to significantly enhance the intrinsic H–resilience of a–IGZO channel by annihilating the native defects. Enabled by the effectively H–resistant AOS TFT, a novel LTPS/AOS integration architecture was tested by stacking the H–resistant IGZO on poly–Si, dubbed metal–oxide–on–Si (MOOS). Comparable electrical characteristics of basic circuits were achieved using both conventional 2D LTPO and 3D MOOS technologies. The significantly reduced layout of the MOOS scheme exhibits a great potential in high–resolution high–PPI displays, especially the next–generation VR/AR/MR displays.

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Last week, Sharp announced that it will expand its alliance with CEC (China Electronics Corp.), the parent company of CEC-Panda, a Chinese TFT LCD panel maker. Sharp sold its Gen 6 line to CEC-Panda back in 2011, and now has decided to play an important role in CEC-Panda’s planned Gen 8 TFT LCD fab in Nanjing. Nanjing CEC-Panda LCD Technology Co., with 17.5 billion RMB ($2.9 billion) in capital, will be a joint venture between CEC Group (92 percent) and Sharp (8 percent), the first joint Chinese-Japanese TFT LCD fab. This follows Samsung and LG Display’s efforts to build Gen 8 fabs in China through joint ventures with TCL and Skyworth, respectively.

With smart handheld devices (smartphones and tablet PCs) growing faster than LCD TV, CEC-Panda is planning to shift its business focus from TV to smart handheld device panels, which require high resolution, slim form factor, low color shift, high color saturation and low power consumption. This shift requires high performance technologies and processes, which Sharp can provide.

Sharp is the first to implement oxide TFT (in particular IGZO) technology for handheld devices, in order to achieve low power consumption and high resolution. Sharp may implement IGZO technology in Nanjing, not only to help the joint venture company to ramp up high resolution panels, but also to collect royalties from any IGZO production.

As we have analyzed, by 2015, there will be 8 Gen 8 fabs in China, at which point China will have the most Gen 8 capacity; one of these will be the CEC-Panda/Sharp line. As the LCD TV market matures, some of these fabs will start to produce high-resolution smart handheld device panels.

Taiwanese panel makers might be further marginalized and forced to reshape their strategy toward the China market. Taiwan panel makers are the largest suppliers to China at present, with LCD TV panels supplied by AUO and Innolux, and smartphone and tablet PC panels supplied by HannStar and CPT. However, with Korean and Japanese makers invested in China, Taiwanese panel makers will be the only ones facing import duties. Taiwan panel makers will be forced to make additional panel cost reductions or somehow create a unique offering in China (such as new TV sizes, or large but lower resolution smart handheld panels).

Today"s PC monitors typically use a thin film transistor (TFT) array made with amorphous silicon, the same type of non-crystalline material found in products like solar cells. According to a report spotted by Tom"s Hardware and Wccftech from a Chinese publication on Sina.com, BOE, whose business includes making display panels for smartphones and tablets for the likes of LG and Apple, has been working on making it more efficient to replace the silicon TFT active layer with an oxide TFT one, allowing the company to make a monitor prototype that can refresh 1920×1080 pixels 500 times per second.

"Oxide semiconductor display technology has the advantages of high mobility, low off-state current, simple process technology, and large size, which can meet the dual needs of future product quality improvement and energy consumption reduction and has become an inevitable trend in technology and market development," the Sina.com report reads, based on a Chinese-to-English translation by Google.

The display panel maker is reportedly able to use oxide TFT LCDs to fight bright spots, increase panel reliability, and reduce power consumption by as much as 15 percent. However, Sina.com"s report pointed to various types of displays BOE is working on, including a 13.3-inch 4K one, so it"s unclear if all these features carry over to the 500 Hz prototype. Advertisement

Should BOE bring its 500 Hz panel to market, it wouldn"t be the first time we"ve seen oxide TFT technology used in monitor development. For example, in 2011, Samsung used an oxide TFT-LCD to make a 4K monitor prototype that ran at 240 Hz, something the company is realizing with the Odyssey Neo G8 32-inch gaming monitor this year.