Measuring Carrier Density in InPâ€based Materials by Using EDTA Solution in Electrochemical Capacitor Voltage Testing

Abstract

The quick test and evaluation of carrier density and its distribution is an important part in the fabrication of photonic integrated devices. Ammonium tartrate is commonly used as the corrosion fluid when electricity chemistry capacitance voltage analysis (ECV) was used to measure the carrier density of InPâ€based epitaxial wafer. However, it has the shortcomings of trivial preparation process, volatilization, slow etching rate, which seriously influence the efficiency of the test. Hence, we have adopted a new solution, which is called as ethylenediamine tetraacetic acid disodium (EDTA). We experimentally demonstrated that the EDTA solution has the advantages of convenience, high efficiency and good stability. And, it can significantly reduce the etching time, thus improving the ECV test efficiency and reducing the production cycle and device fabrication cost.