| 摘要 |
PURPOSE:To integrate a semiconductor laser and a driving circuit, by providing electrical element isolation by using a semi-insulating substrate, forming a semiconductor embedding layer at one side surface of a mesa part including an active layer, and forming a semiconductor epitaxial layer at the other side surface. CONSTITUTION:A mesa part is constituted by a semi-insulating InP substrate 1, a P-type InP clad layer 2, an InGaAsP active layer 3 and an N-type InP second layer 4. A P-type InP embedded layer 5, which has the same conducting type as that of the first clad layer and has the forbidden band width larger than that of the active layer, is formed at the side surface of the mesa part. The layer 5 is electrically connected with the first clad layer 2. The confining effect of the refractive index of light emitted from the active layer 3 is obtained. An N-type InP collector layer 6, a P-type InGaAsP base layer 7 and an N-type InP emitter layer 8 of an HBT are formed at the other side surface of the mesa. A groove is formed down to the substrate 1 in order to isolate a semiconductor laser (a) and the HBT electrically, and a polyimide buried region 9 is formed.
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