PURPOSE: To lessen the amount of scatter of the current amplification factor and reduce the stray capacity at the circumference of a collector and then, makes it pos sible to operate at great speed by forming a base layer of a transistor before a protrud ing form of a laser part is formed so that both electrodes of the laser part may be taken out from the surface of a substrate by using a semi-insulation substrate.
CONSTITUTION: An n-type layer 103 makes possible the epitaxial growth on a semi- insulation substrate 101 and the n-type layer 103 is used as an n-type clad layer of a laser device 1 and also is used as a collector layer of a transistor 2. And an active layer 104 of the laser device and a p-type optical waveguide layer 105 are laminated and among them, the active layer 104 is used as a part of the collector layer and the p-type waveguide layer 105 is used as a base layer in the transistor 2. Then, after forming a p-type clad layer 106 of the laser device, it is selectively etched into the form of a stripe and the laser part 1 is made up and after that, this device allows an emitter layer 111 comprising an extensive transistor to grow and a stripe-like protrusion of the laser device is buried in its layer. As the base layer of this transistor is formed at the first time, it may have uniform characteristics.
ONAKA SEIJI
SHIBATA ATSUSHI
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