Method of fabricating a semiconductor device including a process of adjusting fet characteristics after forming the fet

摘要

A fabricating method of a semiconductor device includes preparing a compound semiconductor substrate including an active layer epitaxially grown on the substrate, forming a test element group FET (TEGFET) having a characteristic value on the compound semiconductor substrate and measuring a characteristic value of the TEGFET, forming an FET having a characteristic value on the compound semiconductor substrate, measuring the characteristic value of the FET, obtaining a variation of the carrier concentration of the active layer of the FET relative to a required value by comparing the measured characteristic value of the FET with reference data obtained from the TEGFET and correcting the variation by implanting ions under conditions that correct the variation. Therefore, after forming a gate electrode of the FET, the carrier concentration of the active layer of the FET is corrected, so the the yield of the device is improved.