在薄膜晶体管(Thin film transistor,TFT)的公共电极制程中,有部分TFT样品的漏电流(I_(off))异常偏高,该部分样品经历同一个光刻胶剥离设备,导致该设备暂停流片,造成产能损失。明确该剥离设备造成TFT漏电流偏高的原因并予以解决,对产能...在薄膜晶体管(Thin film transistor,TFT)的公共电极制程中,有部分TFT样品的漏电流(I_(off))异常偏高,该部分样品经历同一个光刻胶剥离设备,导致该设备暂停流片,造成产能损失。明确该剥离设备造成TFT漏电流偏高的原因并予以解决,对产能和品质确保具有积极意义。本文首先收集了异常设备剥离液和正常设备的剥离液并分析成分,发现异常设备的剥离液中Al离子含量高。其次,发现TFT的I_(off)会随着在异常设备流片次数的增加而上升。其原因是Al离子在剥离制程生成Al_(2)O_(3)颗粒,该颗粒附着在TFT器件钝化层上形成寄生栅极效应,最终造成I_(off)增加。最后,结合TRIZ输出解决方案,并优选方案进行改善验证。实验结果表明,剥离液中的Al离子浓度由1×10^(-8)上升到2.189×10^(-6)时,I_(off)由3.56 pA上升到7.56 pA。当剥离液中含有Al离子,经历的剥离次数增加时,I_(off)呈上升趋势。钝化层成膜前的等离子体处理功率增强、钝化层膜厚增加可以抑制I_(off)增加。由此,可以确定剥离设备造成I_(off)偏高的原因是剥离液中的Al离子形成的寄生栅极效应,钝化层成膜前处理强化和膜厚增加均可以抑制该效应。展开更多
In this work, we investigate the back-gate I-V characteristics for two kinds of NMOSFET/SIMOX transistors with H gate structure fabricated on two different SOI wafers. A transistors are made on the wafer implanted wit...In this work, we investigate the back-gate I-V characteristics for two kinds of NMOSFET/SIMOX transistors with H gate structure fabricated on two different SOI wafers. A transistors are made on the wafer implanted with Si^＋ and then annealed in N2, and B transistors are made on the wafer without implantation and annealing. It is demonstrated experimentally that A transistors have much less back-gate threshold voltage shift △Vth than B transistors under X-ray total dose irradiation. Subthreshold charge separation technique is employed to estimate the build-up of oxide charge and interface traps during irradiation, showing that the reduced AVth for A transistors is mainly due to its less build-up of oxide charge than B transistors. Photo- luminescence （PL） research indicates that Si implantation results in the formation of silicon nanocrystalline （nanocluster） whose size increases with the implant dose. This structure can trap electrons to compensate the positive charge build-up in the buried oxide during irradiation, and thus reduce the threshold voltage negative shift.展开更多
文摘在薄膜晶体管(Thin film transistor,TFT)的公共电极制程中,有部分TFT样品的漏电流(I_(off))异常偏高,该部分样品经历同一个光刻胶剥离设备,导致该设备暂停流片,造成产能损失。明确该剥离设备造成TFT漏电流偏高的原因并予以解决,对产能和品质确保具有积极意义。本文首先收集了异常设备剥离液和正常设备的剥离液并分析成分,发现异常设备的剥离液中Al离子含量高。其次,发现TFT的I_(off)会随着在异常设备流片次数的增加而上升。其原因是Al离子在剥离制程生成Al_(2)O_(3)颗粒,该颗粒附着在TFT器件钝化层上形成寄生栅极效应,最终造成I_(off)增加。最后,结合TRIZ输出解决方案,并优选方案进行改善验证。实验结果表明,剥离液中的Al离子浓度由1×10^(-8)上升到2.189×10^(-6)时,I_(off)由3.56 pA上升到7.56 pA。当剥离液中含有Al离子,经历的剥离次数增加时,I_(off)呈上升趋势。钝化层成膜前的等离子体处理功率增强、钝化层膜厚增加可以抑制I_(off)增加。由此,可以确定剥离设备造成I_(off)偏高的原因是剥离液中的Al离子形成的寄生栅极效应,钝化层成膜前处理强化和膜厚增加均可以抑制该效应。
文摘In this work, we investigate the back-gate I-V characteristics for two kinds of NMOSFET/SIMOX transistors with H gate structure fabricated on two different SOI wafers. A transistors are made on the wafer implanted with Si^＋ and then annealed in N2, and B transistors are made on the wafer without implantation and annealing. It is demonstrated experimentally that A transistors have much less back-gate threshold voltage shift △Vth than B transistors under X-ray total dose irradiation. Subthreshold charge separation technique is employed to estimate the build-up of oxide charge and interface traps during irradiation, showing that the reduced AVth for A transistors is mainly due to its less build-up of oxide charge than B transistors. Photo- luminescence （PL） research indicates that Si implantation results in the formation of silicon nanocrystalline （nanocluster） whose size increases with the implant dose. This structure can trap electrons to compensate the positive charge build-up in the buried oxide during irradiation, and thus reduce the threshold voltage negative shift.
