利用低溫微波退火活化製作奈米級 CMOS TFTs元件的研究

Abstract

在本論文中，我們提出利用低溫微波的退火技術，此技術主要應用於源╱汲極摻雜的活化之用。吾人首先探討了活化製程對超薄鍺磊晶層所引起的影響。吾人發現, 相較於其他的高溫製程,使用低溫微波退火技術可以有效的將基板中的硼離子活化，並且不會傷害到純鍺磊晶層，，不會因為退火製程導致鍺磊晶層被破壞。 這一項先進的低溫微波活化技術，相較於傳統式快速熱退火活化與爐管式退火活化所需要的熱積存比較小，並且因為低溫的關係可以有效的改善短通道效應及貫穿效應，使元件上的尺寸微縮製作因為低溫製程而有所突破。另外，此論文也製作出金屬閘極的薄膜電晶體。在此一研究上可以將金屬閘極薄膜電晶體元件尺寸，有效的微縮至奈米等級的元件，並且在本論文中提出使用先進的低溫微波活化技術，可以獲得相對於傳統式的退火活化有更好的電特性，低溫微波活化技術有效的抑制短通道效應及貫穿效應，有效的提高元件的開/關電流比至107 。

In this thesis, a low temperature microwave annealing technique is proposed. One of the major applications of this technique is for the dopant activation of the source/drain region. First of all, influence of the dopant activation process for the ultra thin epi-Ge layer is presented. By using the low-microwave annealing technique, the boron could be activated very well without damaging the pure epi-Ge layer, as compared to those by the conventional high temperature process. The corresponding thermal budget of the innovation annealing technique is much lower than those of conventional rapid thermal annealing and furnace annealing. In addition, the nanoscale fabrication could be easily realized because the punch-through characteristics and short-channel effect could be suppressed by this proposed technique. In addition, we can fabricate nanoscale metal gate TFTs with excellent transfer characteristics, which is better than those by conventional high temperature process. The punch-through characteristics and short-channel effects could be improved and the Ion/Ioff ration could increased to up to 107 at the same time.