基于0.15μm SOI工艺的耐高温短沟器件设计与实现

Design and Implementation of High Temperature Resistant Short Channel Device Based on 0.15μm SOI Process

绝缘体上硅(Silicon on insulator,SOI)技术在200~400℃高温器件和集成电路方面有着广泛的应用前景,但对于沟道长度≤0.18μm的短沟道器件在200℃以上的高温下阈值电压漂移量达40%以上,漏电流达μA级,无法满足电路设计要求。本文研究了基于0.15μm SOI工艺的1.5 V MOS器件电特性在高温下的退化机理和抑制方法,通过增加栅氧厚度、降低阱浓度、调整轻掺杂漏离子注入工艺等优化方法,实现了一种性能良好的短沟道高温SOI CMOS器件,在25~250℃温度范围内,该器件阈值电压漂移量<30%,饱和电流漂移量<15%,漏电流<1 nA/μm。此外采用仿真的方法分析了器件在高温下的漏区电势和电场的变化规律,将栅诱导漏极泄漏电流效应与器件高温漏电流关联起来,从而定性地解释了SOI短沟道器件高温漏电流退化的机理。

Silicon on insulator(SOI)technology has a wide range of application prospects in 200-400℃high-temperature devices and integrated circuits.However,for short channel devices with chan⁃nel length≤0.18μm,the threshold voltage drift is more than 40%at high temperatures above 200℃,and the leakage current is up to microampere level,which cannot meet the circuit design requirements.In this paper,the degradation mechanism and suppression method of electrical characteristics of 1.5 V MOS devices under high temperature based on 0.15μm SOI process were studied.By increasing gate oxygen thickness,reducing well concentration,adjusting lightly doped drain injection process and oth⁃er optimization methods,a short-channel high temperature SOI CMOS device with good performance was realized.In the temperature range of 25-250℃,the threshold voltage drift is less than 30%,satu⁃ration current drift is less than 15%,leakage current is less than 1 nA/μm.In addition,simulation methods were used to analyze the change law of the drain potential and electric field of the device at high temperature,and the gate-induced drain leakage(GIDL)effect was associated with the high tem⁃perature leakage current of the device,thereby the mechanism of high temperature leakage current degradation of SOI short channel device was qualitatively clarified.