轻掺杂漏LDD MOSFET的工艺及特性

THE TECHNOLOGY AND CHARACTERISTICS OF LDD MOSFET

对LDD MOSFET的两种形成技术——侧向刻蚀和边墙技术进行了分析和比较,证明了边墙技术对控制轻掺杂区域长度具有更高的精确性;同时,利用边墙技术和全离子注入工艺,在硅栅NMOS工艺基础上,成功地制得了1μm沟道长度的LDD MOSFET.测试结果表明,LDD MOSFET击穿电压高于常规MOSFET 3V以上,同时阈值电压的短沟效应明显减小.这些优点意味着LDD MOSFET结构在VLSI中有着广泛的应用前景.

Lightly Doped Drain (LDD) MOSFET developed from the conventional MOSFET, is a new structure for MOS devices. Some short channel effects including the hot electron effect in this new structure can be restrained effectively. In this paper a comparison between overcut etching and side wall technology for LDD MOSFET is given. It shows that the side wall technology is a more precise one to control the length of the lightly doped drain region. Combining the side wall technology with the Si-gate NMOS technology, the LDD MOSFET with 1 micrometer channel length is mada successfully. The results of test show that the breakdown voltage of LDD MOSFET is higher than that of the conventional MOSFET over 3 volts and the short channel effects of the threshold voltage are restrained obviously. The LDD MOSFET is a suitable structure for VLSI.