|
We have successfully demonstrated a 21.3-inch UXGA (1600× RGB × 1200) LTPS AMLCD
我们已经成功地制造出21.3英寸的UXGA（1600×RGB×1200）LTPS 的LCD显示屏
Abstract摘要
We have successfully demonstrated a 21.3-inch UXGA (1600× RGB × 1200) LTPS AMLCD manufactured by non-lasercrystallization method. 我们已经成功地使用非激光结晶法生产制造出21.3英寸UXGA（1600×RGB×1200）LTPS的 LCD显示屏。The gate and data drivers were made ofCMOS TFTs. Gate-driver circuits composed of shift registers andbuffer circuits were integrated on both sides of panel for dualdriving method and the multiplexing circuit was implemented onits data circuits. The non-laser technique such as nanocap-assisted crystallization is promising for low-cost LTPS on glass,compared to conventional laser annealing process.
1. Introduction介绍
Many efforts have been focused on developing high qualitypolycrystalline silicon (poly-Si) films on large area glasssubstrates in order to obtain high-performance poly-Si thin filmtransistors (TFTs) for active-matrix liquid crystal displays(AMLCD) and active-matrix organic light-emitting diodes(AMOLED).我们付出了许多努力，也一直专注于研究发展高品质的多晶硅（多晶Si）薄膜，为了获得大面积的高性能的聚-Si薄膜的玻璃基板，我们一直在针对有源矩阵液晶薄膜晶体管（TFT）显示器（AMLCD）方面来进行研究。
（AMOLED）。 As a result, system on glass (SOG) with memories,sensors and controllers as well as driver circuits has been alreadydeveloped with high-performance poly-Si TFTs [1].
It is widely recognized that the high-quality poly-Si films canbe obtained via various crystallization methods from the as-deposited amorphous silicon (a-Si) films [2,3]. 人们普遍认识到，高品质的多晶硅薄膜能够通过各种结晶方法的沉积非晶硅（的a-Si）薄膜[2,3]来获得。Among them, theexcimer laser annealing (ELA) process has been extensivelyinvestigated and is adapted in mass production lines for AMLCDand AMOLED because it produces high-quality poly-Si films onthe glass substrates at low-temperature. However, there are stillunsolved issues in ELA process, such as high manufacturing cost,uniformity over a large area, high surface roughness, anddegradation in TFT performance under bias stress. Unlike theELA process, it is recognized that Ni silicide-mediatedcrystallization (SMC) can provide device-quality poly-Si filmsthat can be used for high quality poly-Si TFTs with enhanced TFTuniformity and reduced surface morphology at low temperaturedue to the reduced metal contents in the crystallized poly-Si films.[4].
In this paper, we propose nanocap-assisted crystallization(NAC) technique.在本文中，我们提出辅助研究的结晶（TAC）的技术。 This process includes (1) forming of SiO2nanocap layer on a-Si:H films, (2) sputtering of ultra-low density of Niparticles on SiO2nano cap/a-Si:H, and (3) inducing Ni-inducedcrystallization of a-Si through thermal annealing process. Wesuccessfully demonstrated a 21.3-inch UXGA (1600 × RGB ×1200) LTPS TFT-LCD based on NAC processFig. 1. A schematic illustration of NAC of a-Si using aSiO2nanocap layer: (a) deposition of a-Si/SiO2on glass;(b) formation a SiO2nanocap layer by O2plasmatreatment; (c) Ni deposition by RF sputtering; (d)crystallization by FE-RTP.
2. Nanocap-Assisted Crystallization (NAC)Nanocap辅助结晶（NAC）技术
Figure 1 shows a schematic of the SMC of a-Si using a SiO2nanocap layer. 图1主要的描述了示意性的SMC上的一个站点所使用纳米SiO2帽层的特点。SiO2buffer (300nm) and a-Si:H layers (50nm)were deposited successively on 370 × 470 mm2glass substratewith 0.5 mm thickness. Then, SiO2nanocap layer was formed byO2plasma treatment on a-Si by using the capacitively coupledPECVD process (13.56MHZ) at a pressure of 800 mTorr. Thethickness of SiO2nanocap layer was ~2.9 nm. Ni particles on SiO2nanocap layer were deposited by RF sputtering in a N2environment and their densities were from 1013cm-2to 1014cm-2.Finally, this sample was annealed for crystallization in a field-enhanced rapid thermal process (FE-RTP) system. It is reportedthat Ni diffusing through the SiO2nanocap layer down to the a-Silayer can form NiSi2crystallites which enhance the crystallizationvelocity of a-Si films [5].
Figure 2 shows the grain shape of the NAC poly-Si filmsobtained by the optical microscope. 图2显示了通过NAC技术下，聚科学的光学显微镜下得到的薄膜的晶粒形状。The samples were heated in aFE-RTP system. The average grain size was ~100 . The detailsof crystallization process of a-Si are summarized in as nucleationand disk-like grain growth [6].
Fig. 3. AFM image of a NAC poly-Si (a) and ELA poly-Si 一个NAC多晶-Si（a）和ELA多晶Si的原子力显微镜图像
(b).Figure 3 shows the atomic force microscope (AFM) imagesof NAC poly-Si films and a typical ELA poly-Si films. The ELApoly-Si was obtained by twenty times irradiations with the energydensity of 440 mJ/cm2. The root-meat-square (RMS) surfaceroughness of NAC poly-Si films and ELA poly-Si are 2.16 and12.8 nm, respectively. In ELA poly-Si films, the rough surface isrelated with the protrusions at the grain boundaries, which areassociated with the fact that (1) the grain boundaries are the lastpart of the crystallization of the molten Si and (2) the density ofmolten Si is larger than that of solid Si [7]. On the other hand, thesmooth surface of NAC poly-Si films may be associated with thefact that the SMC is accomplished by solid-phase crystallization(SPC) in which Ni-silicide transforms a-Si films into poly-Si filmswithout melting of Si during the entire process. It is reported thatthe hot-carrier reliability can be improved if poly-Si TFTs havesmoother surfaces of poly-Si films [8]. Note that the poly-Si byMICC is quite stable under hot carrier bias stress
|
 |
|||
| 网站地图 |
