US 5,309,464 AGranted

Semiconductor laser and method for manufacturing the same

AssigneeGold Star Co., Ltd.

InventorHyun C. Ko

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Abstract

A semiconductor laser including a semiconductor substrate, a back reflection layer formed over the semiconductor substrate, a first clad layer formed over the back reflection layer, an active layer formed over the first clad layer, the active layer having a width smaller than that of the first clad layer, and a second clad layer formed over the active layer. The second clad layer has a flat upper surface and a width identical to that of the first clad layer. A front reflection layer is formed over the second clad layer. The semiconductor laser also includes impurity diffusion regions of a first conductivity type and a second conductivity type. The impurity diffusion regions extend from the upper surface of the second clad layer to predetermined depth portions of the first clad layer and are in contact with opposite side portions of the active region, respectively. First and second electrodes adapted to oscillate laser beams are formed over the first and second conductivity type impurity diffusion regions. A third electrode adapted to discharge laser beams and a fourth electrode adapted to discharge laser beams are formed over the front reflection layer and beneath the bottom surface of the semiconductor substrate, respectively.

Claims30

Dependent claims

A semiconductor laser comprising:

a semiconductor substrate;
a back reflection layer disposed over the semiconductor substrate;
a first clad layer disposed over the back reflection layer;
an active layer disposed over the first clad layer, the active layer having a width smaller than that of the first clad layer;
a second clad layer formed over the active layer, the second clad layer having a flat upper surface and a width substantially identical to that of the first clad layer;
a front reflection layer disposed over the second clad layer;
a first impurity diffusion region of a first conductivity type extending from an upper surface of the second clad layer to a predetermined depth portion of the first clad layer, the first impurity diffusion region being in contact with a first side portion of the active region;
a second impurity diffusion region of a second condutivity type extending from an upper surface of the second clad layer to a predetermined depth portion of the first clad layer, the second impurity diffusion region being in contact with a second portion of the active region;
a first electrode adapted to oscillate laser beams and disposed over an upper surface of the first conductivity type impurity diffusion region;
a second electrode adapted to oscillate laser beams and disposed over an upper surface of the second conductivity type impurity diffusion region;
a third electrode adapted to discharge laser beams and disposed over the front reflection layer;
and
a fourth electrode adapted to discharge laser beams and disposed beneath a bottom surface of the semiconductor substrate.

10 more elements

A method for manufacturing a semiconductor laser, comprising the steps of:

preparing a compound semiconductor substrate;
forming a back reflection layer having a multi-layered structure over the compound semiconductor substrate;
forming a first clad layer over the back reflection layer;
forming an active layer having a multi-layered structure over the first clad layer, the active layer having a width smaller than that of the first clad layer;
forming a second clad layer over substantially entire resultant exposed surface formed after the formation of the active layer, the second clad layer having a flat upper surface;
forming a first mask pattern over the second clad layer such that a portion of the upper surface of the second clad layer disposed near one side of the active layer is exposed through the first mask pattern;
implanting first impurity ions of a first conductivity type in the exposed upper surface portion of the second clad layer and diffusing the first impurity ions to form an impurity diffusion region of the first conductivity type extending from the upper surface of the second clad layer to a predetermined depth portion of the first clad layer, the first conductivity type impurity diffusion region being in contact with the one side of the active layer;
removing the first mask pattern and forming a second mask pattern over the second clad layer such that a portion of the upper surface of the second clad layer disposed near the other side of the active layer is exposed through the second mask pattern;
implanting second impurity ions of a second conductivity type in the exposed upper surface portion of the second clad layer disposed near the other side of the active layer and diffusing the second impurity ions to form an impurity diffusion region of the second conductivity type extending from the upper surface of the second clad layer to a predetermined depth portion of the first clad layer, the second conductivity type impurity diffusion region being in contact with the other side of the active layer;
forming a front reflection layer having a multi-layered structure over a portion of the upper surface of the second clad layer disposed over the active layer;
forming a first electrode and a second electrode over the first conductivity type impurity diffusion region and the second conductivity type impurity diffusion region, respectively, each of the first and second electrodes having a width smaller than that of each corresponding impurity diffusion region;
and
forming a third electrode and a fourth electrode over the front reflection layer and beneath the compound semiconductor substrate, respectively, the third and fourth electrodes having widths substantially the same as the widths of the front reflection layer and the compund semiconductor substrate, respectively.

10 more elements

Dependencies are inferred from the claim text.