摘要
双栅氧LDMOS器件刻蚀过程中极易造成多晶硅残留现象,降低了栅极和源区之间的击穿电压。改进了制备双栅氧LDMOS器件的方法,对于70 nm以下的栅氧厚度,采用保留整个厚栅氧器件区域栅氧的刻蚀方法,同时用一次多晶工艺代替二次多晶工艺,消除了多晶硅残留现象,减少了工艺步骤,提高了成品率;对于厚度大于70 nm或者100 nm的厚栅氧器件,除了以上的改进措施,还增加了一步光刻工艺,分别单独形成高压和低压器件的源漏区域。通过这些方法,解决了多晶残留问题,得到了性能更好的LDMOS器件,大大提高了成品率。
There is mostly some poly left on the region between gate and source when etching double gate oxide of LDMOS, which debase the break down voltage between gate and source. The fabrication process of LDMOS with double gate oxide down. For devices with gate oxide below 70 nm, The etching method that preserving the gate oxide on the whole region high voltage devices lie on was taken. Also we transfer double poly process to single. By which we reduce process steps and improve yield. For those beyond 70 nm or 100 nm, except for above measures, we add one more patterning step, so that we can implant ion into source/ drain region of low voltage devices and high voltage devices separately. By these methods, we obtain doublegate-oxide LDMOS with better performance, and improve the fabrication yield.
出处
《半导体技术》
CAS
CSCD
北大核心
2008年第9期784-786,共3页
Semiconductor Technology
基金
国家重点基础研究发展计划资助项目(2003CB314705)
关键词
双栅氧刻蚀
LDMOS
栅源台阶高度
多晶残留
etching of double gate oxide
LDMOS
step between gate and source region
poly left
