Showing posts with label display. Show all posts
Showing posts with label display. Show all posts

Friday, July 2, 2021

Future foldable and flexible Display with NCD’s ALD encapsulation technology

In the global market of smart phones, competition on mobile’s form factors has been an important issue since foldable smart phones had launched following cured ones. Samsung electronics applied in-folding form factor to Galaxy Fold and Galaxy Z Flip, and Huawei used out-folding form factor to Mate X. New two or three folding form factor has been unveiling to the public beyond in-folding and out folding displays.

Flexible displays consist of Thin Film Transistor (TFT), Organic Light Emission Diode (OLED) and multi encapsulation layers. Generally organic and inorganic laminated layers is used for foldable displays and PECVD has applied to deposit inorganic materials.

Basically, Inorganic layers is lack of brittleness then their encapsulation property is degraded with continuous mechanical stress. ALD method for TFE was considered instead of PECVD due to their excellent encapsulation characteristics with thicknesses of few tens of nanometers. The reliability of the tool blocked applying to production at that time.

But because of the superior encapsulation property using ALD, many universities, institutes as well as display companies have been developing ALD inorganic layers for flexible displays and evaluating hundreds of thousand times folding test considering actual use recently.

LucidaTM GD Series ALD

The customer which has NCD’s Lucida GD Series ALD, measured folding test on flexible displays with inorganic layers using ALD instead of using PECVD and showed great performance under actual display operation. The 5.85 inch AMOLED display panels for in-folding and out-folding consisted of encapsulation structure of 30nm Al2O3 ALD/ 8㎛-Polymer/ 30nm Al2O3 and was tested in-folding and out-folding evaluation of 200,000 times with bending radius of 2R under light status after the 1st reliability test of RA 60℃/90% for 500hr. There were no dark spots on the panels after finishing the folding measurement. The 2nd reliability test of RA 60℃/90% for 48hr followed folding evaluation and then the TFE status was examined without any cracks.

Using NCD’s large area batch ALD system for foldable phones could obtain superior encapsulation property and flexibility with very thin inorganic layers to current ones using PECVD as well as provide great productivity because the batch tool can process lots of panels at one time.

Then NCD really looks forward to applying its large area batch ALD technology to encapsulation of future flexible display with in/out-folding and very small bending radius because of having solved the previous issues without both reliability and productivity that the reason is why ALD equipment didn’t apply for mass production of flexible display.

Tuesday, October 15, 2019

High device performance of unique ALD-IGZO TFTs to look forward to expanding application area to semiconductor

Amorphous In-Ga-Zn-O (IGZO) materials have been mainly employed as channel materials for the backplane TFTs of flat panel displays (FPDs) owing to their superior characteristics of excellent uniformity, high on/off current ratio, and superior carrier mobility to other amorphous oxide semiconductors. Recently, IGZO thin films have been actively researched for high-end future electronic applications such as TFTs of DRAM and NAND which are typical semiconductor memory devices as well as transparent flexible displays, sensors and logic architectures.

Especially, considering indispensable three dimension architectures of the memory devices for high functional AI semiconductors, the interest in application of IGZO TFTs has been rapidly increased because they are satisfied with the requirement of low power consumption and low operation temperature.

The atomic layer deposition (ALD) method is resulting in better film quality even at a lower deposition temperature. Furthermore, the film thickness and composition can always be precisely controlled at the atomic scale with excellent conformality and higher film density. However, ALD process for IGZO as multi-component materials has the difficulty of control between metal precursors and oxidants.

Variations in transfer curves with the lapse of stress time for 104 s under PB(T)S conditions for Dev. (a) A(1:1:1) and B(1:1:3) at RT and for Dev. (c) A and (d) B at 60℃. (VGS= +20V, VDS= 10.5 V)*

The targeted atomic compositions (In:Ga:Zn) of ALD-IGZO films were acquired by controlling the ALD cycle ratios using the unique ALD method to clear this issue. The device employing (1:1:3) composition exhibited the most desirable characteristics from the viewpoint of excellent bias stability, and they were found to be superior to those by the conventional sputtered-deposited IGZO TFTs.

Therefore, this method to control the compositions of IGZO could be a core technology to guarantee high performance and robust stability for various future ALD-IGZO thin film applications.

Si wafer based batch ALD cluster system

NCD has been developing high throughput batch ALD-IGZO system using the unique technology capable of controlling the designed atomic compositions of IGZO for etch applications. This system could provide the excellent quality competiveness and functional stability as well as high throughput in production of 3D complex architectures such as future Logic, DRAM and NAND devices expected to apply ALD-IGZO thin films.

*Journal of Materials Chemistry C, 2019, 7, 6059, Cationic compositional effects on the bias-stress stabilities of thin film transistors using In-Ga-Zn-O channels prepared by atomic layer deposition, Seung-Bo Ko, Nak-Jin Seong, Kyujeong Choi, So-Jung Yoon, Se-Na Choi, and Sung-Min Yoon. DOI: 10.1039/c9tc01164a

Link :

Wednesday, April 17, 2019

NCD’s ALD IGZO TFTs exhibit remarkable stabilities

NCD Co., Ltd, a global equipment and technology provider of ALD (Atomic Layer Deposition), has developed oxide Thin Film Transistors (TFTs) using In-Ga-Zn-O (IGZO) channels.

IGZO oxide TFTs have rapidly been increased interest in these days, as LTPO oxide TFTs have been adapted for state of the art displays like apple watches as well as IGZO is the most applicable for future transparent flexible devices due to its high mobility and optical transparency. However, IGZO thin films are required to meet the various properties such as higher resolution, large-area uniformity, and better device stability with ultra-thin and flexible structures. Atomic layer deposition (ALD) has recently been reported as a replacement for the conventional sputtering method for fabricating IGZO thin films. The sputtering deposition has some problems such as uniformity issues in thickness and composition, degradation of properties by plasma damages and non-uniformity in the magnetic field, and stability issue of the sputtering target. While ALD-IGZO could show film thickness and composition control in atomic scale, high film conformity and excellent thickness uniformity on large area substrates because ALD is dominated by a self-limiting growth mechanism.

Figure 1: (a) Structure of IGZO TFT and microscopic cross-sectional view of IGZO TFT by Lucida GD Series ALD

Figure 2: a) Comparisons of the IDS–VGS transfer characteristics and IGS gate leakage currents between the devices using ALD IGZO channels with thicknesses of 6 and 10 nm. (b) IDS–VDS output characteristics for the TFT using 6 nm-thick IGZO channel.(*)

NCD has developed oxide TFTs using very thin In-Ga-Zn-O channels, and the excellent device characteristics and the reliable bias temperature stabilities can be successfully obtained. Such a remarkable device stabilities of TFTs with the IGZO channel prepared by the ALD process can help extend the employment of IGZO TFTs for various applications.(*)

NCD’s Lucida GD Series ALD which can run up to 6th generation substrates (1500x1850mm2) could be the best ALD coating solutions for IGZO channels since it’s very compatible, reliable, and producible on large area applications. NCD could provide the most advanced ALD-IGZO technology with its technological knowledge and experience to the customers who are seeking competitive ALD-IGZO systems for current LTPO applications or large-area OLED displays as well as for future flexible transparent displays.

Figure 3: Lucida™ GD Series ALD

* RSC Adv., 2018, 8, 25014, Investigations on the bias temperature stabilities of oxide thin film transistors using In–Ga–Zn–O channels prepared by atomic layer deposition, So-Jung Yoon, Nak-Jin Seong, Kyujeong Choi, Woong-Chul Shin, and Sung-Min Yoon. DOI: 10.1039/c8ra03639j

Monday, April 1, 2019

Integration of high-k dielectric materials in a-IGZO thin film transistors by ALD

High field-effect mobility of Amorphous Oxide Semiconductor Thin Film Transistors (AOS TFT’s) has become more critical in switching devices for active matrix OLED’s (AMOLED). 
Out of many AOS materials, stable a-IGZO (Indium Gallium Zinc Oxide) TFT’s has shown high performance in display devices. However, the process integration of TFT’s is very complicated where a high number of parameters are to be considered and optimized to obtain maximum device performance. Therefore, it is essential to develop each process step through various device structure of thin film transistors using Back Channel Etch and self-aligned TFT. 
An example: Magnified image of the AMOLED screen on the Google Nexus One smartphone using the RGBG system of the PenTile matrix family (Wikipedia).
Currently, incorporation of high–k dielectric materials such as Al2O3 and HfO2 as a passivation layer and gate insulating material shows promising results in obtaining high performance of TFT’s in terms of low operating voltages, bias stability and reducing degradation by isolation from the external environment. A primary focus is on Al2O3 films by ALD technique, where the doping of film to the active layer (a-IGZO) is investigated through back channel etch (BCE) device structure by two different deposition temperatures followed by annealing studies. The performance of the self-aligned TFT's is primarily determined by the two factors :
I. Deposition temperatures of the passivation layer (Al2O3) 
II. Etching rate. 
The conclusions drawn from the studies of BCE applied to a-IGZO 10% O2 aelf–aligned (SA) device structures where Al2O3 layer deposited by ALD at 150 °C as a gate insulating material. The electrical characteristics of fabricated Thin Film Transistors are obtained to be very promising for further engineering applications. 
A deep study and understanding of each step in process flow and significance of Atomic Layer Deposition gave a fruitful insight into many aspects.
Guest Blog by: Ravi Pendurthi, imec, Leuven, Belgium LinkedIn Profile

Sunday, November 4, 2018

AP Systems to supply Thin Film Encapsulation to Samsung Display QD-OLED line

DIGITimes China reports [LINK] that Samsung Display is building a large-scale quantum dot organic light-emitting diode (QD-OLED) panel pilot production line. The line is scheduled to be finished in December 2018 and will be activated after 6 months (mid 2019). According to the report the supply ration from Korean equipment manufacturers has increased significantly for this line.

As an example the the report claims that AP Systems beat Applied Materials to supply the Thin Film Encapsulation (TFE) equipment. AP Systems has previously supplied TFE equipment for the 8th generation RGB OLED TV panel production line (V1) of Samsung Display. In the past Samsung Display has used TFE equipment supplied by Applied Materials in the 6th generation flexible OLED production line, but has now switched and for its AP Systems in this 8th generation QD-OLED test production line.

Also according to the report, the PECVD equipment will be supplied by Wonik IPS from Korea whereas the blue OLED material evaporation equipment will be supplied by Canon Tokki (Japan) and the red and green QD material inkjet printing machine will come from Kateeva (USA).
The KORONA™ TFE System running PEALD with "Multi-linear Nozzle" technology and ICP antenna design technology (high density/low damage plasma).
For TFE AP Systems are using a Plasma enhanced Atomic Layer Deposition (PEALD) technology on their KORONA™ TFE System. The system is capable of depositing a film structure that acts as a sealant to prevent oxygen and moisture penetration into OLED device. Based on a 1000Å, SiNx/SiOx multi-layer structure the Water Vapor Permeability is less than 5e-5 g/m2/day.
According to AP Systems they can also apply the film as a flexible sealant to realize flexible, rollable, and foldable displays. 

Thursday, October 25, 2018

NCD contracted to supply new ALD equipment for production of µ-OLED with LG Display

Korean ALD equipment manufacturer, NCD reports new order of µ-OLED ALD equipment from LG Display

"NCD has recently contracted with LGD to supply µ-OLED manufacture equipment which is new Lucida GuD Series for Al2O3-ALD encapsulation to avoid OLED degradation induced water and oxygen. Newly introduced Lucida GuD is high volume batch-type ALD equipment based on the process and hardware of OLED encapsulation technology of Lucida GD Series.

µ-OLED produced by this system is micro display with high resolution for augmented reality(AR) and virtual reality(VR) and has been expected the huge application and market in the future.

Otherwise, manufacture of µ-OLED requests high productivity like display industry therefore ALD tools with high film quality and low throughput for Semiconductor couldn’t meet the need of the customers and the market. So NCD is more expecting that this µ-OLED is next growth engine market because it has high volume ALD equipment and excellent OLED encapsulation technology.

NCD will lead µ-OLED ALD equipment market with this starting point and continue to make efforts to become the world’s best specialized ALD technology company.”

LucidaTM GuD Series

Monday, April 16, 2018

NCD Contracted with TIANMA to supply 6G half ALD equipment for flexible OLED encapsulation

NCD recently signed a contract with TIANMA, one of Chinese leading display manufacturers, to provide 6G half ALD equipment for encapsulation of flexible OLEDs in the next six months to Wuhan TIANMA. This is a follow-up order to purchase NCD's 6G half (1500mmX925mm) ALD equipment, which is based on the superior performance evaluation of earlier installed 5.5G class ALD equipment in Shanghai TIANMA.

The performance of ALD encapsulation by the existing equipment showed excellent film uniformity as well as excellent moisture permeability and step coverage, compared to that by PECVD, and was qualified by the customer's flexible OLED products.

This proves that NCD's ALD core technology and the reliability of equipment have been recognized by its customer.
It is challenging to realize device reliability using current encapsulation technology deposited by PECVD for the next generation flexible OLED devices, since it requires bending, folding and rolling, ALD technology will be an essential choice for future flexible OLED products with its excellence and competitiveness.

NCD will make the Lucida GD series become the standard ALD equipment for all flexible OLED encapsulation based on these needs, and continue to grow into the world's most professional ALD Company with new challenges and developments. 
Cluster system for Lucida™ GD series

Wednesday, November 29, 2017

Transparent flexible capacitors by ALD high-k, ALD AZO and graphene electrodes

Transparent and flexible flat panel displays manufactured on plastic substrates and flexible substrates involve key technologies like ALD manufacturing of transparent electrodes and barriers. In addition, for the pixel-drive circuit of displays, capacitors are used for charging and discharging at very high speed. Having a high capacitance enables also a high color brightness for each pixel. Now researchers at Wuhan University, China has developed an capacitor technology that is has an excellent transparency and flexibility using the latest ALD and graphene processing technology. Please find the Open Access publication below.

In this study used comercially available graphene in the form of single-layer graphene that had been grown by CVD on copper foil from 2D Carbon Tech Inc. LTD, Changzhou, China. The ALD ZrO2 high-k and AZO was grown in an TSF 200 from Beneq.

Transparent and Flexible Capacitors with an Ultrathin Structure by Using Graphene as Bottom Electrodes
by Tao Guo, Guozhen Zhang, Xi Su, Heng Zhang, Jiaxian Wan, Xue Chen, Hao Wu and Chang Liu
Nanomaterials 2017, 7(12), 418; doi:10.3390/nano7120418  (registering DOI) - 28 November 2017
(Left) The schematic diagram of the ultrathin, transparent and flexible capacitors; (Right) The optical transmittance spectra of the capacitors on PEN substrates. The inset shows the optical photograph of the actual capacitor device with the characters “TFS 200” in the background, and the optical transmittance spectra of graphene and capacitors on quartz substrates. 
Ultrathin, transparent and flexible capacitors using graphene as the bottom electrodes were directly fabricated on polyethylene naphthalate (PEN) substrates. ZrO2 dielectric films were deposited on the treated surface of graphene by atomic layer deposition (ALD). The deposition process did not introduce any detectible defects in the graphene, as indicated by Raman measurements, guaranteeing the electrical performances of the graphene electrodes. The Aluminum-doped zinc oxide (AZO) films were prepared as the top electrodes using the ALD technique. The capacitors presented a high capacitance density (10.3 fF/μm2 at 10 kHz) and a relatively low leakage current (5.3 × 10−6 A/cm2 at 1 V). Bending tests revealed that the capacitors were able to work normally at an outward bending radius of 10 mm without any deterioration of electrical properties. The capacitors exhibited an average optical transmittance of close to 70% at visible wavelengths. Thus, it opens the door to practical applications in transparent integrated circuits. Full article

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Saturday, December 17, 2016

LG Display partner with Apple, Google and Microsoft for foldable OLED displays

Previously this year there have been a number of rumors that OLED display manufacturers will start using ALD barriers in production of next generation smartphone display. Now recent reports suggest that LG Display will start supplying foldable OLED displays for tablet sized smartphones (see tweet below) that can be folded to a typical smartphone format. Until now there has been no reports on ALD barriers for this one but one can assume that it is a good opportunity for ALD to be developed for these type of extreme display applications.

ETN News Reports : It is confirmed that LG Display has partnered up with Apple and google and is developing ‘out-foldable’ displays for Smartphones. It is going to start mass-producing them in 2018 and supply them to Apple, Google, and Microsoft. It is predicted that Samsung Display and LG Display will compete against each other in order to grab upper hands in markets for foldable displays.
According to an industry on the 15th, LG Display is currently developing out-foldable panels for Smartphones. Unlike how Samsung Display is working with Samsung Electronics’ Wireless Business Department, LG Display is developing foldable devices with outside businesses such as Apple, Google, and Microsoft.

Full story : LINK


Friday, November 25, 2016

Novel high-speed ALD outperforms current techniques for making displays

The Holst Centre in the Netherlands reports: Fast and industry-compatible, spatial atomic layer deposition (sALD) promises to revolutionize production of thin-film displays. Now researchers at Holst Centre have shown that sALD can deliver semiconductor layers with better performance than physical vapor deposition (PVD) at the same – and potentially even higher – throughputs. An easily scalable, atmospheric-pressure process, sALD could soon become the preferred method for creating large-area thin-film and flexible devices. 

A key step in producing next-generation ultra-high definition) displays is the creation of a highly uniform layer of an amorphous oxide semiconductor such as indium-gallium zinc oxide (IGZO). Today, this is typically done using a PVD technique known as sputter deposition. Sputtering requires expensive vacuum equipment and can also prove difficult to correctly control material composition and thickness over large areas. This results in variable transistor performance, particularly in thin film applications such as displays.

Now Holst Centre has shown that sALD offers an industry-compatible alternative which improves display performance and at the same time could cut production costs. The team has used the technique to create semiconductor layers with charge carrier mobilities (a key measure of semiconductor performance) of 30 to 45 cm2/Vs. This compares to typical mobilities around 10 cm2/Vs for sputtering. The sALD layers also exhibited low off current, switch-on voltages around 0 V and excellent bias stress stability.

"Spatial ALD offers all the performance advantages of traditional ALD – superior control of layer thickness and composition, large-scale uniformity and unparalleled conformability – but at 10-100 times the speed. So a typical 50-nm thick layer can be produced within the standard 1 minute window demanded by today's industrial processes," said Paul Poodt, Program Manager sALD at Holst Centre.

"The performance of sALD means semiconductor layers could become much thinner, enabling even higher throughputs and lower material consumption," added Gerwin Gelinck, Program Director Flexible and Large Area Transistor Electronics at Holst Centre. "In fact, its performance characteristics are preserved even when scaling down the semiconductor thickness to less than 5 nm. This can lead to novel semiconductor structures, such as super-lattices, with even higher electron mobilities."

The Holst Centre team and partners are now taking steps towards the upscaling and commercialization of these sALD processes and related equipment.

Tuesday, September 6, 2016

High-throughput Large-Area Spatial ALD by Beneq from Finland

Beneq announced their new fast Spatial ALD reactor in November last year (Beneq introduces the next revolution in industrial ALD). End of July Beneq released more information in the ALD2016 Ireland exhibition

Large-area sheet-to-sheet spatial ALD system (From Beneq Blog)

Beneq is a pioneer in ALD solutions that enable coating of large substrates, and we have also discussed them here in the blog. Beneq’s Mikko Söderlund was showcasing our innovations in this area to the ALD2016 audience.

Our large-area spatial ALD coating equipment has been developed for high-throughput coating applications such as Zn buffer for CIGS solar cells, OLED encapsulation, glass coating, and rear-surface passivation of crystalline solar cells. The new spatial ALD process makes it possible to coat bigger substrates faster and in a more flexible way. The capacity of the new large-area ALD coating equipment really opens doors to new possibilities in industrial-level coating. You can check the latest results of our large-sheet ALD tests from Mikko’s poster.

The large area spatial ALD reactor from Beneq (picture from Beneq)

The above deposition speeds result in massive area throughput figures. For rear-surface passivation (with a thin 5 nm Al2O3 coating) as a case example, processing wafers at substrate speeds exceeding 20 m/min would allow a single piece of equipment to produce over 30 000 wafers per hour. That is fast by any standard. (from Beneq Blog)

Download Mikko's ALD2016 poster to get all the details of the latest spatial ALD pilots with large substrates.

I met with Beneq at the ALD2016 Exhibition to discuss the new spatial ALD reactor (Picture Fotografie Katharina Knaut).

Wednesday, August 31, 2016

NCD to deliver Lucida GD series ALD system for OLED encapsulation with Chinese display manufacturer, TIANMA

NCD reports today (8/31 2016) :The OLED market is going to prospect fast gigantic growing in the near future because OLED has the possibilities of bending, folding and various forms like circle, therefore it will be applied for flexible and wearable devices. Flexible OLEDs need excellent thin encapsulation layers in order to keep the property from the permeation of water and oxygen under the external environment using repeated bending, folding and rolling of devices. However, the current encapsulation based on PECVD is not satisfied with future flexible OLEDs, so new encapsulation technology would absolutely be required.

Many OLED manufactures are currently reviewing to use ALD technology because of obtaining the highest property from the encapsulation layers of OLED, but they have not been solving the low throughput and particle issues followed by using their ALD systems.

In order to clear these problems, NCD has completed to develop the 6th ALD equipment for thin film encapsulation which satisfies high quality, large area and high throughput applying for the inventive ALD technology, and we have been also continuously testing customer’s samples. NCD’s ALD encapsulation layer shows much better properties than that of PECVD, and the encapsulation capability on application for foldable products has been confirmed from the customers. As a result, NCD has recently entered into the contract with Chinese display manufacturer, TIANMA to supply the 5.5th generation class ALD system of Lucida GD series for thin film encapsulation of OLED. It apparently shows that NCD’s core technologies and the result of developments have been approved by the oversea customer.

NCD will keep doing our best to set Lucida GD series as the standard of all of flexible OLED encapsulation equipment with this achievement and become the number one global ALD Company with the best competitiveness making new challenges and developments.

Lucida™ GD Series ALD

High throughput atomic layer deposition system for OLED displays 

Cluster system for Lucida™ GD series


  • Barrier layer(Al2O3, TiO2) for flexible substrate
  • WVTR(water vapor transmission rate) 5.3x10-5g/m2·day (tritiated water test @30nm Al2O3/PEN substrate)
  • Encapsulation layer(Al2O3,TiO2) for OLED
  • Applications of mass-product


  • High throughput : > 30 panels/hour
  • Substrate size : > 6G (1500 x 1850mm2)


  • Advanced process kit and small volume chamber for short gas cycle times
  • Extremely materialize ALD mechanism
  • Small foot print
  • Totally integrated process module
  • Easy process control

Technical specifications