Manufacture of varactor diode

Abstract

Abstract PURPOSE: To make voltage-capacity characteristics linear by laminating and growing a N - -type layer whose impurity density decreases gradually in its growing direction and a N ++ layer on a N ++ -type semiconductor substrate, and by forming a P - -type region on the N - -type layer which has sloping impurity density after removing the substrate. CONSTITUTION: On N ++ -type GaAs substrate 1, N - -type layer 7 is formed whose impurity density is high at the substrate-1 side and decreases linearly in the growing direction, and N ++ -type layer 8 is grown on it. Then, substrate 1 is removed by being lapped and etched, and on grown layer 8, high-impurity-density grown layer 7 is exposed whose impurity-density distribution profile is reversed after the growth. Next, P-type layer 4 is diffusion-formed here, and ohmic electrode 5 and ohmic electrode 6 are adhered onto the surface and the reverse surface of layer 8 respectively and then, mesa-etched to obtain the varactor diode. Consequently, since no sudden change in impurity density distribition occurs, its capacity variation is large and linearity can be obtained. COPYRIGHT: (C)1979,JPO&Japio

Inventors

• 👤 Takeshi Suzuki
• 👤 Hironobu Hatakeyama
• 👤 Takashi Ishii

Bibliographic Details