Photocoupling semiconductor device

Abstract

Abstract PURPOSE:To provide a photocoupling semiconductor device which has an easy drivability and less waveform deformation even with low signal level by employing a bi-directional phototransistor as a photoreceptor when forming a photocoupler in combination of a semiconductor light emitting element and a photoreceptor. CONSTITUTION:An N<+>-type semiconductor substrate 7 is employed as the substrate of a bi-directional phototransistor 3 for enhancing the injection efficiency at the collector side in reverse direction, and a P-type base layer 8 is epitaxially grown thereon. Then, an annular groove 10 perforated in the substrate 7 is formed on the surface of the layer 8, an N<+>-type layer 11 is diffused from the side wall to the bottom of the groove 10, and the layer 8 is isolated in an island state. Thereafter, an N<+>-type emitter region 9 is formed in the layer 8, a surface protective film 14 is coated on the entire surface including the groove 10, an opening is perforated thereat, an emitter electrode 13 is mounted on the region 9, and a collector electrode 12 is mounted on the back surface of the substrate 7. Then, a GaAs light emitting element 1 having a P<+>-type region 4, an N-type substrate 5, and metallic electrodes 6a, 6b is formed through a transparent glass 2 on the region 8, and is integrated with the phototransistor 3.

Inventors

• 👤 Shintaro Takase

Bibliographic Details