2013 SID 可靠性文献阅读 王 玲 2013-06-08
OUTLINE Oxide TFT 可靠性 NBIS 机理 两种工艺改善措施 AC 华南理工成果展 LCD 机械应力可靠性 玻璃
Oxide TFT 可靠性-NBIS (1) 机理 Photo-generated hole-electron pairs Light absorption due to defect levels Solution 1: reduce trap-oxygen vacancy Solution 2: introduce a transparent shield layer Hole capture by the traps in insulator Solution : high quality insulator
Oxide TFT 可靠性-NBIS (2) Japan M.Tsubuku c-axis aligned crystalline (CAAC) IGZO Reduction in Amount of Hydrogen in GI Film Without (a) / with Reduction in Amount of Hydrogen in GI Film, stress voltage Vg =-30 V, T= 80℃, a white LED at 3000 lx
Oxide TFT 可靠性-NBIS (3) 台湾交通大学 M.-Y. Tsai Introducing a Transparent UV Shielding Layer Mo-doped ZnO ( ZnO/MoO 3 = 98:2 wt.%, MZO)
Oxide TFT 可靠性-NBIS (4) The function of MZO Absorb the light wavelength around UV-light regime – better than black matrix Isolate from the ambient environment
Oxide TFT可靠性-AC (1) Bipolar AC stress 与DC/unipolar AC stress的关系 unipolar AC stress-pulse width Bipolar AC stress- f, duty ratio E. K.-H. Yu, University of Michigan,16.3
Oxide TFT可靠性-AC (2) Bipolar AC=unipolar positive AC+ unipolar negative AC 可简化模型, Guess:Recovery必须考虑,正负AC stress 可能独立
Oxide TFT可靠性-AC (3) Unipolar stress : PBS,70℃,△Vth 先正后负; Unipolar stress : NBS,70℃ NBS时间越长, △Vth 越负,更多的空穴进入oxide中
Oxide TFT可靠性-AC (4) bipolar stress :时间越大,△Vth越负 频率越大,△Vth越负,PBS/NBS 都短 Bipolar AC stress: Duty 越小, △Vth 越小,PBS时间短,NBS时间长,但△Vth 漂移仍比较小 说明PBS 对整个stress起决定性作用,可能NBS过程只是将PBS trap的电子拉回来 bipolar stress :时间越大,△Vth越负 频率越大,△Vth越负,PBS/NBS 都短 来回穿的次数多,可能是产生了trap
LCD-glass 机械应力可靠性 应力集中会引起脆性材料断裂;使物体产生疲劳裂纹 Thinner glass-必要性 加应力至失效 机械应力与形状,应力加载方式有关 不同测试方法 提出失效机理 Loading force-stress 指导工作 确定工作范围 改进器件 [63.3 / K. H. Vepakomma]
LCD-glass 机械应力可靠性 测试方法: Loading force-stress Stress gauge –电阻应变仪 four-point bend test –edge strength ring-on-ring test-surface strength Loading force-stress Consider large deflection [ D. I. Wilcox, USA, 63.1] revised stress equations for rectangle glass [K.-C. Chang,taiwan,63.2] Stress gauge –电阻应变仪
Summary 研究热点 NBIS AC 机理仍有争论