标题: 由矽磊晶到极平整之超薄氧化层制作
From low temperature Si epitaxy to atomically smooth ultra-thin oxide
作者: 林柏村
B. C. Lin
蔡中
荆凤德
陈文照
C. Tsai
Albert Chin
W. J. Chen
电子研究所
关键字: 极平整;超薄氧化层;矽磊晶;选择性矽磊晶;氘;atomically smooth;ultra-thin oxide;Si epitaxy;selective Si epitaxy;deuterium anneal;SILC
公开日期: 1998
摘要: 摘要:
我们已经设计一紧密热璧型低压炉管系统,将之用于成长矽磊晶,选择性矽磊晶以及极薄二氧化矽(< 30A)。在晶片表面残存的自然生成氧化层不仅降低磊晶层的品质,其同样对于极薄氧化层的品质有重大的影响.与超高真空化学气相沉积或分子束磊晶相较,我们使用了设计良好的紧密型炉管以及高温氢气热烤去降低炉管中水气及氧气的含量.我们使用此方法,首先在550oC成功的长出与矽基板相同品质矽磊晶.这低温550oC的磊晶可以用来做矽-锗磊晶.使用二氯甲矽皖(SiH2Cl2)去成长选择性磊晶,我们可以在750oC成功的长出这个温度可以用于积体电路的制程.自然生成氧化层将会影响闸极氧化层的品质.由于先去除自然生成氧化层然后再成长热能氧化层,我们得到矽基板与氧化层之间的介面极为平整.使用此一氧化层与传统炉管氧化层相较,有大量的改善载子移动率.在极平整氧化层下,其trap产生的速率以及SILC(stress induce leakage current)同样大量的降低.我们使用氘去取代氢气对闸极氧化层做退火,能够得到更进一步改善这极薄氧化层的品质.由氘气做退火可以降低五倍的SILC效应.
Abstract:
We have designed a leak-tight low pressure hot wall furnace system, which can be used to grow Si epitaxy layer, selective epitaxial Si and ultra-thin silicon dioxide (<30A). The residual native oxide not only degrades the quality of epitaxial material but also extremely important for ultra-thin gate oxide. In contrast to previous ultra-high-vacuum chemical-vapor-deposition or molecular beam epitaxy, we have used a leak-tight design and hydrogen bake to reduce the background moisture and oxygen. We have first successfully grown epitaxial Si at 550oC and the quality of epitaxial film has been found comparable to that of Si substrate. The low temperature of 550 oC is especially chosen because it is suitable for future SiGe epitaxy. The selective epitaxy is achieved at low temperatures by using Dichlorosilane (SiH2Cl2) and a minimum temperature of 750 oC is achieved that is low enough for process integration consideration. The native oxide can strongly influence the gate oxide integrity. By removing the native oxide and re-growing thermal oxide, atomically smooth oxide-Si interface can be achieved. Significant mobility improvement was obtained from these oxides than that from conventional furnace oxidation. The trap generation rate and stress-induced leakage current (SILC) are also much reduced using the atomically smooth oxide. The gate oxide quality of ultra-thin oxide can be further improved by using deuterium annealing instead of traditional forming gas annealing. A factor of five times reduction of SILC is obtained by deuterium annealing.
URI: http://140.113.39.130/cdrfb3/record/nctu/#NT870428125
http://hdl.handle.net/11536/64417
显示于类别:Thesis