Manufacture of planar type semiconductor device

Abstract

Abstract PURPOSE:To provide a planar type semiconductor device having high breakdown voltage by forming laminated insulating films having large and small impurity diffusion coefficients, perforating an opening thereat, forming a polycrystalline layer containing impurity thereon, and diffusing the impurity therefrom into the substrate. CONSTITUTION:An SiO2 film 46 and an Si3N4 film 43 are laminated on an N-type Si substrate 41, a predetermined shape of photoresist film 48 is formed thereon, a dry etching process is conducted thereon with gas plasma to form an opening 42 at the laminated films. Then, a polycrystalline Si layer 49 including Ga is accumulated on the entire surface including the opening 42, is heat treated to diffuse the Ga in the substrate 41 to form a P-type region 44. In this manner the Ga is introduced from the side surface into the film 46 simultaneously when introducing the Ga into the substrate 41 to diffuse the Ga outside of the opening 42, and the P-N junction 45 thus formed may become smoothly curved state having no bending point. Accordingly, the breakdown voltage of the junction 45 may be enhanced.

Inventors

• 👤 Tadashi Utagawa
• 👤 Harue Arai

Bibliographic Details