为了减小绝缘层上硅锗(SGOI)自加热和短沟道效应,提出新型的双台阶式埋氧SGOI n型金属氧化物半导体场效应晶体管(nMOSFET).在该器件结构中,采用双台阶式埋氧结构来减小自加热效应,引入接地层(GP)用于减小漏致势垒降低(DIBL).建立应变硅器件的低场迁移率模型并嵌入到器件模拟器Sentaurus Device中.在不同的沟道应变情况下,分析自加热效应随埋氧层的厚度以及短沟道效应随栅长的变化关系.模拟结果表明,相对于Ge组分为0的情况下,Ge组分为0.4的SGOI器件的输出电流提升了至少50%.随着沟道下方埋氧厚度从100nm减小到10nm,自加热温度减小超过60℃;当引入接地层后,DIBL效应减小超过25%,泄漏电流在很大程度上得到抑制.
A novel device called double step buried oxide (BOX) SGOI n-type metal-oxide-semiconductor field-effect transistor (nMOSFET) was presented in order to eliminate the self-heating and short channel effect of strained Si grown on relaxed SiGe-on-insulator (SGOI). In this structure, a double step buried oxide was constructed below the channel region for minishing self-heating effect. Meanwhile, a ground plane (GP) was introduced below channel buried layer for reducing drain induced barrier lowering (DIBL) effect. A low field mobility model for strained Si device was established and implemented in the device sim- ulator Sentaurus Device. In different cases of channel strain, both self-heating effect as a function of buried oxide thickness and short channel effect as a function of gate length were analyzed. Numerical simulation results indicate that output current of the device with Ge content of 0. 4 increases by more than 50 percent compared with that of the device without Ge content. As buried oxide thickness below the channel region ranges from 100 to 10 nm, the self-heating temperature decreases by over 60 ℃. DIBL effect decreases by more than 25 percent and leakage current is greatly suppressed when a ground plane is involved.