次微米MOS中的熱載子效應

Abstract

隨著半導體技術快速地向深次微米領域發展,我們可預期未來用於MOS電路 的電源電壓將會持續的降低以避免日益嚴重的熱載子可靠度問題, 最近越 來越多人注意並從事著關於低電壓熱載子可靠度的研究, 在本篇論文中我 試著研究在低電壓之下產生熱載子的機制, 除了field-heating之外,我們 將electron-electron scattering和Auger recombination 這兩種機制加 我們的熱載子模式中, 藉由對於介面缺陷分佈和閘極電流這些由熱載子注 入所引起的現像作模擬和量測, 我們將這兩種機制對熱載子生成的影響作 一番評估, 並且, 藉由將模擬和實驗的結果在高汲極偏壓和低汲極偏壓之 下作比較, 我們也將這兩種機制在不同偏壓之下對熱載子可靠度的影響亦 作一番探討, 最後我們所做的結果顯示出, 在較低的汲極偏壓之下,電子 和電子間的交互作用(electron-electron interaction) 有可能顯著的提 高界面缺陷產生之量, 而在一個更低的汲極偏壓之下, Auger effect對閘 極電流有重大的影響. As the semiconductor technology is moving rapidly into deep submicron regime, the power supply voltage used in the MOS circuits is expected to scale down to avoid serious reliability problems caused by hot carriers. Recently, much research effort on low voltage reliability physics has been undertaken. In this thesis, we intend to study new hot carrier generation mechanisms at low drain biases. Two hot electron generation mechanisms, electron-electron scattering and Auger recombination,in addition to channel field-heating are both introduced in our hot carrier model. The hot carrier injection induced interface trap generation and gate leakage current are characterized and simulated to evaluate the above two mechanisms. By comparing simulation with experiment result at high drain biases and low drain biases, the influence of the two mechanisms on hot carrier reliability is investigated. In particular, our study reveals that at a lower drain bias the electron-electron interaction may significantly raise the interface trap generation. At an even lower drain bias,the Auger effect is primerily responsible for a gate leakage current.