| 摘要 |
PURPOSE:To improve the characteristics of a FET b forming an insulating film onto a compound semiconductor base body, to which a FET element is shaped, controlling piezoelectric polarization in the base body by stress from the insulating film and correcting the K value of the FET element and at least one of threshold voltage. CONSTITUTION:Si ions are implanted to a semi-insulating GaAs substrate 1, and activated and thermally treated to form an N type channel layer 2, and a gate electrode 3 is shaped. Si ions are implanted while using the gate electrode 3 as a mask, and activated and thermally treated to form N<+> type source-drain regions 4. An SiO2 film 5 is applied to the substrate 1 and the gate electrode 3, openings are shaped onto the regions 4, and source-drain electrodes 6 are formed. The K value of a FET element shaped and threshold voltage are measured, a difference between SiO2 film thickness required for realizing a target value is obtained, and an SiO2 film 7 is deposited only by the difference between the film thickness. Accordingly, the K value and threshold voltage are corrected easily, thus improving the characteristics of a FET. |
