本文针对大功率垂直腔面发射激光器(vertical cavity surface emitting laser, VCSEL)阵列热阻大、出光不均匀的问题,研究p-GaAs层欧姆接触电阻值的作用机理,降低欧姆接触串联电阻的方法,以提高VCSEL阵列出射光功率的均匀性。基于3种常用欧姆接触金属Ti/Au、Ni/Au、Ti/Al /Ti/Au,研究各层金属厚度和金属组合对与p型欧姆接触电阻的作用规律；结合等离子体表面处理工艺,改变金属/p-GaAs界面态,研究界面态对欧姆接触电阻的影响规律。实验对比分析得到金属Ti/Au结构电极欧姆接触的比接触电阻率最低,为3.25×10-4 Ω·cm²；基于金半接触势垒模型,通过表面等离子体处理,界面势垒可降低12.6%(0.269 2 eV降至0.235 3 eV),等离子体轰击功率可调控金半界面的势垒和态密度。

Aiming at the problems of large thermal resistance and uneven light output of high-power vertical cavity surface emitting laser (VCSEL) array,this paper studies the action mechanism of ohmic contact resistance of p-GaAs layer and the method of reducing ohmic contact series resistance,so as to improve the uniformity of light output power of VCSEL array.Based on three commonly used ohmic contact metals Ti/Au, Ni/Au and Ti/Al /Ti/Au,the effects of metal thickness and metal combination on p-type ohmic contact resistance are studied.Combined with plasma surface treatment process,the inerface state of metal/p-GaAs is improved, the effect of metal/p-GaAs interface state on ohmic contact resistance is studied.The experimental comparative analysis shows that the specific contact resistivity of ohmic contact of metal Ti/Au structure electrode is the lowest,which is 3.25×10-4 Ω·cm².Based on the metal/semiconductor contact potential barrier model,the interface potential barrier can be reduced by 12.6% (0.269 2 eV to 0.235 3 eV) by surface plasma treatment,and the plasma bombardment power can regulate the potential barrier and density of states on the metal/semiconductor interface.

北京市自然科学基金(4202008)资助项目