| 摘要 |
PURPOSE:To obtain a measured value with no scattering and high precision by a method wherein when a sheet resistance or specific resistance of the P-type epitaxial layer is measured by the four-probe method, the epitaxial layer is previously surface- treated with fluoric acid. CONSTITUTION:When a P-type epitaxial layer is grown on an N-type Si substrate and its sheet resistance or specific resistance is measured by the four-probe method, the surface of epitaxial layer is previously etched with fluoric acid. Especially it is desirable that the mixing ratio of fluoric acid to water is 1:1-1:100, and the treatment time is selected in a range from 30sec to 10min. In this way, the resistance of P-type epitaxial layer can be measured without scattering, and the process is especially effective to measure an epitaxial layer of high resistance more than 10OMEGA. It is because it is hard to consider that the oxide film on the surface is removed by the fluoric acid treatment, the reason is not clear, however, said method shows good effect, and the efficiency of measuring the resistance can be improved. |
