Semiconductor laser element and method of manufacturing semiconductor laser element
A semiconductor laser element includes: a window region including a disordered portion formed by diffusion of a group-III vacancy, the diffusion promoted by providing on the window region a promoting film that absorbs a predetermined atom; a non-window region including an active layer of a quantum well structure; and a difference equal to or larger than 50 meV between an energy band gap in the window region and an energy band gap in the non-window region.
1. A semiconductor laser element, comprising: an active layer;
a window region including a disordered portion formed by diffusion of a group-III vacancy, the window region including an impurity free disordered portion of the active layer;
a non-window region including a portion of the active layer having a quantum well structure; and
a layer near the active layer, the layer being doped with an impurity that preferentially substitutes a group-V site,
wherein the impurity that preferentially substitutes the group-V site has a diffusion coefficient equal to or smaller than 3×10 −14 cm 2 /s at a thermal treatment temperature at which the disordered portion is formed, the layer near the active layer is a guide layer formed directly on the active layer, the impurity that preferentially substitutes the group-V site is doped at least on the active layer side of the guide layer, and a concentration of the impurity that preferentially substitutes the group-V site in the guide layer is from 0.1×10 17 cm −3 to 1×10 17 cm −3 , and
wherein a difference between an energy band gap in the window region and an energy band gap in the non-window region is equal to or larger than 50 meV.
2. The semiconductor laser element according to claim 1 , wherein the impurity that preferentially substitutes the group-V site is doped at least on the active layer side of a cladding layer formed above the active layer.
3. The semiconductor laser element according to claim 2 , further comprising a current non-injecting layer that is provided in the midst of the cladding layer or in the midst of a contact layer, constricts a current injected from outside, and supplies the current to the active layer, wherein the cladding layer or the contact layer includes:
a first layer on which the current non-injecting layer is formed; and
a second layer regrown after a surface cleaning process is performed at a temperature of 650° C. or higher after the current non-injecting layer is formed, or a second layer formed by performing regrowth at a temperature of 650° C. or higher.
4. The semiconductor laser element according to claim 1 , wherein the impurity that preferentially substitutes the group-V site is doped at least on the active layer side of a contact layer formed above the active layer to inject a carrier into the active layer.
5. The semiconductor laser element according to claim 4 , further comprising a current non-injecting layer that is provided in the midst of a cladding layer or in the midst of the contact layer, constricts a current injected from outside, and supplies the current to the active layer, wherein the cladding layer or the contact layer includes:
a first layer on which the current non-injecting layer is formed; and
a second layer regrown after a surface cleaning process is performed at a temperature of 650° C. or higher after the current non-injecting layer is formed, or a second layer formed by performing regrowth at a temperature of 650° C. or higher.
6. The semiconductor laser element according to claim 1 , wherein the impurity that preferentially substitutes the group-V site is carbon.
7. The semiconductor laser element according to claim 6 , further comprising a current non-injecting layer that is provided in the midst of a cladding layer or in the midst of a contact layer, constricts a current injected from outside, and supplies the current to the active layer, wherein the cladding layer or the contact layer includes:
a first layer on which the current non-injecting layer is formed; and
a second layer regrown after a surface cleaning process is performed at a temperature of 650° C. or higher after the current non-injecting layer is formed, or a second layer formed by performing regrowth at a temperature of 650° C. or higher.
8. The semiconductor laser element according to claim 1 , wherein the semiconductor laser element has a ridge structure.
9. The semiconductor laser element according to claim 8 , further comprising a current non-injecting layer that is provided in the midst of a cladding layer or in the midst of a contact layer, constricts a current injected from outside, and supplies the current to the active layer, wherein the cladding layer or the contact layer includes:
a first layer on which the current non-injecting layer is formed; and
a second layer regrown after a surface cleaning process is performed at a temperature of 650° C. or higher after the current non-injecting layer is formed, or a second layer formed by performing regrowth at a temperature of 650° C. or higher.
10. The semiconductor laser element according to claim 1 , wherein the guide layer has a function of not inhibiting the diffusion of the group-III vacancy.
11. The semiconductor laser element according to claim 1 , wherein the guide layer is a semiconductor layer.