电化学电容-电压(ECV)法对高铝组分AlGaAs化合物半导体载流子浓度的测量

Measurement of Semiconductor Carrier Concentration of AlGaAs Compound with High Aluminum Component by Electrochemical Capacitance-Voltage(ECV)

电化学电容-电压(ECV)法对测量化合物半导体载流子浓度纵向分布具有重要意义。本文用乙二胺四乙酸二钠(EDTA)电解液对高铝组分AlGaAs化合物半导体单层样品测试,相比钛试剂(Tiron)电解液因为优化了腐蚀均匀性提高了测试的精确度。但对低铝组分AlGaAs化合物半导体单层样品材料测试时,EDTA电解液因腐蚀速率过快不能准确测量载流子浓度,无法替代Tiron电解液进行测试。于是对EDTA电解液进行稀释改良,通过减缓腐蚀速率来实现对低铝组分AlGaAs化合物半导体单层样品材料的载流子浓度测量。分布式布拉格(DBR)样品同时包含高铝组分AlGaAs和低铝组分AlGaAs,笔者实现用EDTA单一电解液对载流子浓度的测量,与二次离子质谱(SIMS)测试比较具有高度一致。本文为ECV对高铝组分AlGaAs化合物半导体材料体系的载流子浓度测量提供了新方法。

The electrochemical capacitance-voltage(ECV)method is very important for measuring the vertical distribution of carrier concentration in compound semiconductor.In this paper,EDTA electrolyte is used to test the semiconductor monollayer sample of AlGaAs compound with high aluminum components.Compared with titanium reagent(Tiron)electrolyte,the accuracy of the test is improved because of the optimized corrosion uniformity.However,EDTA electrolyte cannot accurately measure the carrier concentration due to its fast corrosion rate when testing the semiconductor monolayer sample material of AlGaAs compound with low aluminum component,so it cannot replace Tiron electrolyte.Therefore,EDTA electrolyte is diluted and improved to achieve carrier concentration measurement of low aluminum AlGaAs compound semiconductor monolayer sample material by slowing down the corrosion rate.The distributed Bragg(DBR)sample contains both AlGaAs and AlGaAs with high and low aluminum components.The carrier concentration measured by EDTA single electrolyte is highly consistent with that measured by secondary ion mass spectrometry(SIMS).This paper provides a new method for measuring the carrier concentration of AlGaAs compound semiconductor material system with high aluminum component by ECV.