Controlled two-step solid-phase crystallization for high-performance polysilicon TFT's

Solid-phase crystallization for polysilicon thin-film transistors (TFT's) is generally limited by a tradeoff between throughput and device performance. Larger grains require lower crystallization temperatures, and hence, longer crystallization times. In this letter, a novel crystallization technique is presented which increases both throughput and device performance, using a two-step process, controlled using an in situ acoustic temperature/crystallinity sensor. A high-temperature rapid thermal annealing (RTA) nucleation step is followed by a low-temperature grain growth step to grow large-grain polysilicon. TFT's have been fabricated with a substantial improvement in throughput and device performance. This promises a high-throughput, high-performance, spatially uniform TFT process.

多晶硅薄膜晶体管（TFT）的固相结晶通常受到生产效率和器件性能之间权衡的限制。较大的晶粒需要较低的结晶温度，因此需要更长的结晶时间。在这封信中，介绍了一种新颖的结晶技术，该技术通过一个两步过程提高了生产效率和器件性能，并使用原位声学温度/结晶度传感器进行控制。高温快速热退火（RTA）成核步骤之后是低温晶粒生长步骤，以生长大晶粒多晶硅。已经制造出在生产效率和器件性能方面有显著提高的TFT。这有望实现一种高生产效率、高性能、空间均匀的TFT工艺。