工艺(SiCl4):1、处理硅片2、基座的HCl腐蚀去硅程序(1)N2预冲洗(2)H2预冲洗(3)升温(两步)(4)HCl排空、腐蚀(5)H2冲洗(6)N2冲洗3、外延生长(1)N2预冲洗(2)H2预冲洗
(3)升温(两步)(4)HCl排空、抛光(5)H2清洗(6)外延生长(7)H2清洗-降低自掺杂效应(8)降温(9)N2清洗
反应物和载气(如H2)一起被引入反应器中,而晶片一般维持在650℃到850℃的范围。必须有足够的砷的过蒸汽压,以防止衬底和生长层的热分解。
3.7.1 外延生长原理1 气相外延外延是指在单晶衬底上生长一层新单晶的技术,新单晶的晶向取决于衬底,由衬底向外外延而成。外延方法很多,硅半导体器件中通常采用硅的气相外延法。其过程是:四氯化硅(SiCl4)或硅烷(SiH4),在加热的硅衬底表面与氢发生反应或自身发生热分解,还原成硅,并以单晶形式沉积在硅衬底表面。
2外延生长设备
外延系统应满足如下要求:(1)气密性好(2)温度均匀且精确可控,能保证衬底均匀地升温与降温;(3)气流均匀分布(4)反应剂与掺杂计的浓度及流量精确可控(5)管道、阀门用不锈钢制造,并保证连接可靠。(6)要使用多个流量计使反应剂与掺杂计的浓度及流量精确可控。(7)石墨基座由高纯墨制成。加热采用射频感应加热方式。
1、Genius only means hard-working all one's life. (Mendeleyer, Russian Chemist) 天才只意味着终身不懈的努力。21.5.265.26.202108:3008:30:57May-2108:302、Our destiny offers not only the cup of despair, but the chalice of opportunity. (Richard Nixon, American President )命运给予我们的不是失望之酒,而是机会之杯。二〇二一年五月二十六日2021年5月26日星期三3、Patience is bitter, but its fruit is sweet. (Jean Jacques Rousseau , French thinker)忍耐是痛苦的,但它的果实是甜蜜的。08:305.26.202108:305.26.202108:3008:30:575.26.202108:305.26.20214、All that you do, do with your might; things done by halves are never done right. ----R.H. Stoddard, American poet做一切事都应尽力而为,半途而废永远不行5.26.20215.26.202108:3008:3008:30:5708:30:575、You have to believe in yourself. That's the secret of success. ----Charles Chaplin人必须相信自己,这是成功的秘诀。-Wednesday, May 26, 2021May 21Wednesday, May 26, 20215/26/2021