| 摘要 |
PURPOSE: To obtain a low-noise high-gain MESFET for low current operation use by implanting ions of an n-type dopant at specified dose in a semiinsulating GaAs substrate, having high resistivity at specified ion implanting energy to form channel regions having an abrupt impurity profile. CONSTITUTION: A silicon nitride layer 11 is sputtered on the surface of a semiinsulating GaAs substrate 10, having a high resistivity of about 5×10<7> ohm-cm or more. Ions of Si or other adequate n-type dopants are implanted in the substrate 10 through that layer 11. If the impurity concn. of acceptors in the high-resistance substrate 10 is high and ion implanting condition is adequate, the dopant profile in a channel region 12 becomes abrupt. This raises the mutual conductance gate capacitance ratio at low current, thereby obtaining an MESFET having low-noise and high-gain.
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