Seiko Epson Corporation

Seiko Epson Corporaition

Tatsuya Asaka

Katsumi Mori

Hideaki Iwano

Takayuki Kondo

Takashi Takamura

Tetsuya Seki

A surface emitting semiconductor laser, with a resonator cavity transverse to the planar extent of the deposited layers, is provided with a first reflection mirror on the substrate side composed of alternating layers comprising a first layer that is made of a Group III-V compound semiconductor and a second layer that is made of a Group III-V compound semiconductor with an energy bandgap that is larger than that of the first layer. A second reflection mirror is provided at the opposite end of the cavity adjacent to a column like resonator portion. At least the first reflection mirror comprises a distributive Bragg reflection (DBR) multiple layer mirror that has an interface region between first and second layers having a carrier concentration that is higher than that of other regions. The column like resonator portion is surrounded by a buried layer which may consist of two layers, the first layer functioning as barrier layer and the second layer functioning as a flattening layer. The first layer may be comprised of a silicon compound and the second layer may be comprised of SOG or a resin compound. The multiple layer band structure of the DBR mirror is improved, current easily flows vertically through the multiple layers and the element resistance is low. In addition, a simple and reliable method is employed to fabricate the DBR mirror and the dual buried layer, respectively, because the doping concentration is controlled through dopant gas flow control or is controlled through light and can be easily accomplished without using comparatively high temperature processing.

Surface emitting semiconductor laser and its manufacturing process

Surface emission type semiconductor laser, method and apparatus for

In order to manufacture a surface emission type semiconductor laser, a plurality of semiconductor layers including a multilayered semiconductor mirror, a cladding layer, an active layer and other layers are sequentially formed on a substrate through the organic metal vapor growth method. A photoresist mask is then formed on the semiconductor layers. At least the cladding layer in the semiconductor layers is anisotropically etched by the use of the photoresist mask. At least one column-like portion is thus formed to have sidewalls extending perpendicular to the substrate and to guide the light in a direction perpendicular to the substrate. Thereafter, a buried layer including a single layer formed therein at an area covering at least the sidewalls of the column-like portion is formed around the column-like portion. A multilayered dielectric mirror is deposited in the column-like portion on the light exit end thereof. The multilayered dielectric mirror is disposed at the light exit port of a light exit side electrode. To increase the reflectivity below the light exit side electrode, a multilayered semiconductor mirror may be formed in the column-like portion at a position nearer the light exit side than the cladding layer.

Method of making surface emission type semiconductor laser

Surface emission type semiconductor laser

A surface emission type semiconductor laser includes a plurality of semiconductor layers defining at least one resonator in a direction perpendicular to the semiconductor substrate of the laser, the layers including at least a cladding layer in the semiconductor layers being formed into at least one column-like portion extending in a direction perpendicular to the semiconductor substrate, and a buried layer surrounding the column-like portion. The column-like portion is of rectangular cross-section in a plane parallel to the semiconductor substrate and having longer and shorter sides, whereby the polarization plane of said omitted laser beam is parallel to the direction of said shorter sides.

A surface emission type semiconductor laser includes a plurality of semiconductor layers defining at least one resonator in a direction perpendicular to the semiconductor substrate of the laser, the layers including at least a cladding layer in the semiconductor layers being formed into at least one column-like portion extending in a direction perpendicular to the semiconductor substrate, and a II-VI group compound semiconductor epitaxial layer buried around the column-like portions. 'Lattice mismatch ratio' between the II-VI group compound semiconductor epitaxial layer and the column-like portions is no more than 0.2%, or more preferably no more than 0.16%. The II-VI group compound semiconductor layer is formed from an adduct consisting of II group organometallic compound and VI group organometallic compound and a VI group hydride by the use of a chemical vapor deposition. If a plurality of column-like portions are to be formed by a separation groove, these column-like portions are separated from one another, the II-VI group compound semiconductor epitaxial layer being buried in the separation groove.

A surface emitting semiconductor laser is provided with at least reflection mirrors on the substrate side composed of a first layer that is made of a Group III-V compound semiconductor and a second layer that is made of a Group III-V compound semiconductor with an energy bandgap that is larger than that of the first layer. The first and second layers are alternately stacked. The semiconductor laser is also composed of a distributive reflection multiple layer mirror that has an interface region between first and second layers having a carrier concentration that is higher than that of other regions. As a result, the multiple layer band structure of the distributive reflection mirror has been improved, current easily flows vertically through the multiple layers and the element resistance is low. In addition, a simple and reliable method is employed to fabricate the distributive reflection mirror because the doping concentration is controlled through dopant gas flow control or is controlled through light exposure.

Surface emitting semiconductor laser and method of manufacture

A surface emission type semiconductor laser includes a plurality of semiconductor layers defining at least one resonator in a direction perpendicular to the semiconductor substrate of the laser, the layers including at least a cladding layer in the semiconductor layers being formed into at least one column-like semiconductor layer extending in a direction perpendicular to the semiconductor substrate, and a II-VI group compound semiconductor epitaxial layer buried around the at least one column-like semiconductor layer. If a plurality of column-like semiconductor layers are to be formed by a separation groove, these column-like semiconductor layers are separated from one another, the II-VI group compound semiconductor epitaxial layer being buried in the separation groove.

A surface emission type semiconductor laser includes a plurality of semiconductor layers defining at least one resonator in a direction perpendicular to the semiconductor substrate of the laser, the layers including at least a cladding layer in the semiconductor layers being formed into at least one column-like portion extending in a direction perpendicular to the semiconductor substrate, and a II-VI group compound semiconductor epitaxial layer buried around the column-like portions. The II-VI group compound semiconductor layer is formed from an adduct consisting of II group organometallic compound and VI group organometallic compound and a VI group hydride by the use of a chemical vapor deposition. If a plurality of column-like portions are to be formed by a separation groove, these column-like portions are separated from one another, the II-VI group compound semiconductor epitaxial layer being buried in the separation groove.

A surface emission type semiconductor laser includes a plurality of semiconductor layers defining at least one resonator in a direction perpendicular to the semiconductor substrate of the laser, the layers including at least a cladding layer in the semiconductor layers being formed into at least one column-like portion extending in a direction perpendicular to the semiconductor substrate, and a II-VI group compound semiconductor epitaxial layer buried around the column-like portion. The column-like portion is of rectangular cross-section in a plane parallel to the semiconductor substrate and having longer and shorter sides, whereby the polarization plane of said emitted laser beam is parallel to the direction of said shorter sides.

A microwave ECR plasma etching apparatus having a plasma generating chamber coupled to a separate treatment chamber for supporting a Group II-VI sample to be dry etched, are tailored for the dry etching of Group II-VI compound semiconductors resulting in highly anisotropic etched patterns in Group II-VI materials having vertical side walls taking advantage of the ionicity of the constituents of Group II-VI compounds and utilizing a low ion energy level which will not damage the crystalline integrity of the Group II-VI material. A precleaning step is provided prior to dry etching of the Group II-VI sample thereby enhancing the etching rate of the dry etching treatment. In several embodiments, the microwave ECR plasma etching apparatus includes precleaning apparatus integral with the treatment chamber to preclean the Group II-VI sample surface prior to its transfer, without braking vacuum, to the treatment chamber.

Plasma etching apparatus

A surface emission type semiconductor laser includes a plurality of semiconductor layers defining at least one resonator in a direction perpendicular to the semiconductor substrate of the laser, the layers including at least a cladding layer in the semiconductor layers being formed into at least one column-like light emitting portion extending in a direction perpendicular to the semiconductor substrate, and a II-VI group compound semiconductor epitaxial layer buried around the column-like portion. An active layer of multi-quantum well structure is further formed on the layer section of the cladding layer having the column-like portion. If a plurality of column-like portions are formed, these column-like portions are separated from one another by a separation groove terminating short of the active layer, the II-VI group compound semiconductor epitaxial layer being buried in the separation groove. Particularly, when it is desired to produce a phase synchronization type semiconductor laser, a waveguide layer is formed below the active layer, and the waveguide layer is adapted to propagate light rays in a direction parallel to the active layer.

A surface emission type semiconductor laser includes a plurality of semiconductor layers defining at least one resonator in a direction perpendicular to the semiconductor substrate of the laser, at least a cladding layer in the semiconductor layers being formed into at least one column-like semiconductor layer extending in a direction perpendicular to the semiconductor substrate, and a II-VI group compound semiconductor epitaxial layer buried around the column-like semiconductor layer. The semiconductor laser also includes an exit-side electrode which is formed in contact with a contact layer of the column-like semiconductor layer which has an opening used to form an exit port. The opening is formed in the exit-side electrode at a position including the geometric center of the contact layer and ranging between 10% and 90% of the surface area of the contact layer.

A microwave ECR plasma etching method and apparatus, including a plasma generating chamber coupled to a separate treatment chamber for supporting a Group II-VI sample to be dry etched, are tailored for the dry etching of Group II-VI compound semiconductors resulting in highly anisotropic etched patterns in Group II-VI materials having vertical side walls taking advantage of the ionicity of the constituents of Group II-VI compounds and utilizing a low ion energy level which will not damage the crystalline integrity of the Group II-VI material. The apparatus may further include counter bias means and/or transverse magnetic field means in a region between the plasma generating chamber and the treatment chamber to improve the reactionary quality of the species and lower the energy level of the species without losing control and directionality of the species flow into the treatment chamber thereby preventing damage to the crystalline structure of the etched II-VI sample.

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Suwa, Japan

Tatsuya Asaka