Preparation of semiconductor device

Abstract

Abstract PURPOSE:To improve the quantum efficiency of a germanium element by coating an Si3N4 film for preventing light reflection on a semiconductor substrate when producing a light receiving element and implanting impurity ions through the film to form a PN-junction which has a photoelectric converting function in the substrate. CONSTITUTION:On a P-type germanium substrate 1, an SiO2 film 2 is vapor- grown, a ring-shaped diffusion window 3 is opened by etching and an N-type guard ring 4 is diffusion-formed in the substrate 1 under the window. Next, only the film 2 of the region surrounded by the window 3 is removed, and by using the exposed surface of the substrate 1 as an ion implanting window 5, an Si3N4 film 6 which will later become a light reflection preventing film is vapor-grown all over the surface including the window. Then the part of the surface except the window 5 is covered with a resist film 7, and by using it as a mask, N-type impurity ions are implanted into the substrate 1 to form an N<+>-type region 9, the region 9 is activated sufficiently by removing the layer 7 and heat-treating to produce a perfect PN-junction with a photoelectric converting function between the region and the substrate 1. Next, a window 10 is opened in the film 6, and an Al electrode 11 contacting the end of the region 9 is coated.

Inventors

• 👤 Shuzo Kagawa
• 👤 Takao Kaneda

Bibliographic Details