中国物理B ›› 2012, Vol. 21 ›› Issue (8): 88501-088501.doi: 10.1088/1674-1056/21/8/088501

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Degradation of the transconductance of gate-modulated generation current in nMOSFET

陈海峰, 过立新, 杜慧敏   

  1. School of Electronic Engineering, Xi'an University of Posts and Telecommunications, Xi'an 710121, China
  • 收稿日期:2012-01-15 修回日期:2012-04-27 出版日期:2012-07-01 发布日期:2012-07-01
  • 基金资助:
    Project supported by the Shaanxi Provincial Research Project of Education Department, China (Grant No. 11JK0902) and the Xi'an Municipal Applied Materials Innovation Fund, China (Grant No. XA-AM-201012).

Degradation of the transconductance of gate-modulated generation current in nMOSFET

Chen Hai-Feng (陈海峰), Guo Li-Xin (过立新), Du Hui-Min (杜慧敏 )   

  1. School of Electronic Engineering, Xi'an University of Posts and Telecommunications, Xi'an 710121, China
  • Received:2012-01-15 Revised:2012-04-27 Online:2012-07-01 Published:2012-07-01
  • Contact: Chen Hai-Feng E-mail:chenhaifeng@xupt.edu.cn
  • Supported by:
    Project supported by the Shaanxi Provincial Research Project of Education Department, China (Grant No. 11JK0902) and the Xi'an Municipal Applied Materials Innovation Fund, China (Grant No. XA-AM-201012).

摘要: The degradation of transconductance (G) of gate-modulated generation current IGD in LDD nMOSFET is investigated. The G curve shifts rightward under the single electron-injection-stress (EIS). The trapped electrons located in the gate oxide over the LDD region (QL) makes the effective drain voltage minish. Accordingly, the G peak in depletion (GMD) and that in weak inversion (GMW) decrease. It is found that Δ GMD and Δ GMW each have a linear relationship with the n-th power of stress time (tn) in dual-log coordinate: Δ GMD ∝ tn, Δ GMDtn (n=0.25). During the alternate stress, the injected holes neutralize QL induced by the previous EIS. This neutralization makes the effective VD restore to the initial value and then the IGD peak recovers completely. Yet the threshold voltage recovery is incomplete due to the trapped electron located over the channel (QC). As a result, GMW only recovers to the circa 50% of the initial value after the hole-injection-stress (HIS). Instead, GMD is almost recovered. The relevant mechanisms are given in detail.

关键词: generation current, transconductance, electron injection, alternate stress, degradation

Abstract: The degradation of transconductance (G) of gate-modulated generation current IGD in LDD nMOSFET is investigated. The G curve shifts rightward under the single electron-injection-stress (EIS). The trapped electrons located in the gate oxide over the LDD region (QL) makes the effective drain voltage minish. Accordingly, the G peak in depletion (GMD) and that in weak inversion (GMW) decrease. It is found that Δ GMD and Δ GMW each have a linear relationship with the n-th power of stress time (tn) in dual-log coordinate: Δ GMD ∝ tn, Δ GMDtn (n=0.25). During the alternate stress, the injected holes neutralize QL induced by the previous EIS. This neutralization makes the effective VD restore to the initial value and then the IGD peak recovers completely. Yet the threshold voltage recovery is incomplete due to the trapped electron located over the channel (QC). As a result, GMW only recovers to the circa 50% of the initial value after the hole-injection-stress (HIS). Instead, GMD is almost recovered. The relevant mechanisms are given in detail.

Key words: generation current, transconductance, electron injection, alternate stress, degradation

中图分类号:  (Semiconductor-device characterization, design, and modeling)

  • 85.30.De
85.30.Tv (Field effect devices)