Photo coupling semiconductor device

Abstract

Abstract PURPOSE:To enable to prevent the malfunction due to pulse impression by increasing the sensitivity to a light and reducing the effect by the electrostatic coupling between a light emitting and a light receiving element by improving the structure of a P-N junction which generates a photocurrent by receiving the light. CONSTITUTION:A photo diode as the light receiving element has two P-N junctions, the P-N junction due to an N type epitaxial layer 1 and a P<+> type diffused region 5 and the P-N junction electrically in parallel relation therewith and due to the P<+> type diffused region 5 and an N<+> type diffused region 7 extended on this P<+> type diffused region 5. By such a structure, the upper surface part of the P<+> type diffused region 5 is, except the contact part thereof, covered with the extended N<+> type diffused region 7, and the capacitor is formed mainly to an N type, therefore the effect by the electrostatic coupling on the light receiving element is reduced. Besides, it follows that this structure has the two P-N junctions, which is useful also to improve the sensitivity with respect to the light of the photo diode.

Inventors

• 👤 Toshibumi Yoshikawa
• 👤 俊文 吉川
• 👤 Masaru Kubo
• 👤 勝 久保
• 👤 Hisao Nagao
• 👤 長尾　久夫
• 👤 Nobuhiro Nishimoto
• 👤 宜弘 西本

Bibliographic Details