Canon Kabushiki Kaisha

Shoichi Kawashima

Yasuhiro Nagatomo

Katsuyuki Hoshino

Takeshi Kawashima

The method of producing a GaN-based microstructure includes a step of preparing a semiconductor structure provided with a trench formed in a main surface of the nitride semiconductor and a heat-treating mask covering a main surface of the nitride semiconductor excluding the trench, a first heat-treatment step of heat-treating the semiconductor structure under an atmosphere containing nitrogen element to form a crystallographic face of the nitride semiconductor on at least a part of a sidewall of the trench, a step of removing the heat-treating mask after the first heat-treatment step and a second heat-treatment step of heat-treating the semiconductor structure under an atmosphere containing nitrogen element to close an upper portion of the trench on the sidewall of which the crystallographic face is formed with a nitride semiconductor.

Method of producing microstructure of nitride semiconductor and photonic crystal prepared according to the method

A process for forming a microstructure of a nitride semiconductor including (1) preparing a semiconductor structure which has a second semiconductor layer formed of a group III nitride semiconductor containing at least Al formed on a principal plane of a first semiconductor layer formed of a group III nitride semiconductor containing no Al, and which has a hole that penetrates through the second semiconductor layer and is formed in the first semiconductor layer; (2) subjecting the semiconductor structure to heat treatment under a gas atmosphere including a nitrogen element after step (1) to form a crystal plane of the group III nitride semiconductor containing no Al, on at least a part of a side wall of the hole; and (3) forming a third semiconductor layer formed of a group III nitride semiconductor on the second semiconductor layer after step (2) to cover the upper part of the hole.

Process for forming microstructure of nitride semiconductor, surface emitting laser using two-dimensional photonic crystal and production process thereof

Provided is a two-dimensional photonic crystal surface emitting laser that enables easy laser oscillation with two-dimensionally symmetric intensity distribution, using a photonic crystal of a lattice structure having different lengths of primitive translation vectors in plane, realized in a two-dimensional photonic crystal surface emitting laser including an active layer, and a two-dimensional photonic crystal having a two-dimensionally periodic refractive index profile disposed in a vicinity of the active layer. The two-dimensional photonic crystal has a lattice structure where two primitive translation vectors in plane have different lengths, a shape of a member forming lattice points included in a unit cell of the lattice structure has anisotropy with respect to directions of the two primitive translation vectors, and the anisotropy of the shape of the member permits a difference of a coupling coefficient to be smaller than a case where the shape of the member is isotropic.

Two-dimensional photonic crystal surface emitting laser

There are provided a process for producing a semiconductor device and a semiconductor device which allow conductivity distribution to be formed without making refractive index distributed even in a material system of a semiconductor difficult to be subjected to ion implantation. The process for producing a semiconductor device includes the steps of forming a semiconductor layer containing a dopant; forming a concave and convex structure on the semiconductor layer by partially removing the semiconductor layer; and forming a conductivity distribution reflecting the concave and convex structure in the semiconductor layer by performing heat treatment on the semiconductor layer in which the concave and convex structure has been formed at a temperature at which a material forming the semiconductor layer causes mass transport and filling up a hole of a concave portion of the concave and convex structure with the material forming the semiconductor layer.

Process for producing semiconductor device and semiconductor device

A nitride semiconductor surface-emitting laser includes a two-dimensional photonic crystal layer having a resonant mode in an in-plane direction. The surface-emitting laser includes an active layer, the two-dimensional photonic crystal layer, a semiconductor layer, and an electrode in this order. The two-dimensional photonic crystal layer contains p-type conductive InGaN (0&#x2266;x&#x2266;1) as a high-refractive-index medium. The semiconductor layer contains p-type conductive InGaN (0&#x2266;y&#x2266;1). The thickness tof the two-dimensional photonic crystal layer satisfies the relation of t&#x2267;(&#x3bb;/n), wherein &#x3bb; denotes the lasing wavelength, and ndenotes the effective refractive index of the resonant mode.

Nitride semiconductor laser

A laser structure is provided in which an influence caused by a concave-convex structure on laser characteristics is reduced when the Epitaxial Lateral Overgrowth (ELO) technique is applied to a photonic-crystal surface emitting laser. A height of the mask structure is set such that a reflection peak wavelength of 0-th order diffracted light and a reflection peak wavelength of first-order diffracted light differ from each other for light that enters a concave-convex periodic structure, which is constituted by a first layer and a mask structure, from a photonic crystal. Further, reflection intensity of the 0-th order diffracted light from the concave-convex periodic structure is larger than reflection intensity of the first-order diffracted light from the concave-convex periodic structure at an oscillation wavelength &#x3bb;.

Photonic-crystal surface emitting laser, laser array using the laser, and image forming apparatus using the laser array

A surface emitting laser emitting a laser beam in a single transverse mode irrespective of an emission area while one-dimensionally aligning polarization of the output beam, including a two-dimensional photonic crystal, having resonance modes in directions of the primitive translation vector aand a, lengths |a| and |a| of the primitive translation vectors aand asatisfied |a|=p&#xd7;(&#x3bb;/2n), |a|=&#x3bb;/2ndescribed by a resonance wavelengths &#x3bb;and &#x3bb;in the resonance modes in the aand adirections, effective refractive indexes nand ndetermined by the resonance modes in the aand adirections, an integer p of 2 or more, the resonance wavelengths &#x3bb;and &#x3bb;satisfy &#x3bb;&#x2266;2&#xd7;(n/(n+n))&#xd7;&#x3bb;described by the effective refractive index nand a refractive index nof an external medium located out of the surface emitting laser.

Surface emitting laser

A surface emitting laser array having a plurality of surface emitting lasers arranged in an array, each of the surface emitting lasers being provided with a two-dimensional photonic crystal having a resonance mode in an in-plane direction and with an active layer. The surface emitting laser has a mesa-shaped inclined side wall surface. When a maximum light-receiving angle with respect to the mesa-shaped inclined side wall surface at which an incident light is coupled with a waveguide containing the two-dimensional photonic crystal is denoted as &#x3b8;max&#xb0;, an angle formed by a plane of the two-dimensional photonic crystal and the mesa-shaped inclined side wall surface is controlled so as to exceed (90+&#x3b8;max)&#xb0; or be smaller than (90&#x2212;&#x3b8;max)&#xb0;.

Surface emitting laser array and production method therefor

A manufacturing method of a microstructure which enables production of a deep and narrow microstructure in a GaN semiconductor with high precision is provided. The manufacturing method of a microstructure for forming a microscopic structure in a semiconductor has a configuration having a first step of forming a first GaN semiconductor layer on a substrate, a second step of forming a first hole by using etching on the first GaN semiconductor layer formed in the first narrow, and a third step of performing heat-treatment at a temperature from 850&#xb0; C. to 950&#xb0; C. inclusive under a gas atmosphere including nitrogen, in order to form a second narrow in which a diameter of the first hole h formed in the second step is made narrower than the diameter of the first hole in an in-plane direction of the substrate.

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Kawasaki, Japan

Shoichi Kawashima