摘要:
A method of preparing a nitride semiconductor capable of forming a nitride-based semiconductor layer having a small number of dislocations as well as a small number of crystal defects resulting from desorption with excellent crystallinity on the upper surface of a substrate through a small number of growth steps is proposed. The method of preparing a nitride-based semiconductor comprises steps of forming a mask layer on the upper surface of a substrate to partially expose the upper surface of the substrate, forming a buffer layer on the exposed part of the upper surface of the substrate and the upper surface of the mask layer and thereafter growing a nitride-based semiconductor layer. Thus, the outermost growth surface of the nitride-based semiconductor layer laterally grown on the mask layer does not come into contact with the mask layer. Therefore, desorption hardly takes place from the outermost growth surface of the nitride-based semiconductor layer, whereby a nitride-based semiconductor layer having a small number of defects is formed. Further, the mask layer is directly formed on the substrate, whereby the number of growth steps for the nitride-based semiconductor layer is reduced.
摘要:
A nitride-based semiconductor element enabling formation of a nitride-based semiconductor layer having low dislocation density, consisting of a material different from that of an underlayer, on the underlayer with a small thickness is obtained. This nitride-based semiconductor element comprises a plurality of mask layers formed at a prescribed interval to be in contact with the upper surface of the underlayer while partially exposing the underlayer and the nitride-based semiconductor layer, formed on the upper surface of the underlayer and the mask layers, consisting of the material different from that of the underlayer. The minimum distance between adjacent mask layers is smaller than the width of an exposed part of the underlayer located between the adjacent mask layers.
摘要:
A nitride-based semiconductor element having excellent element characteristics is obtained by obtaining a nitride-based semiconductor layer having excellent crystallinity without performing a long-time etching process. This nitride-based semiconductor element comprises a mask layer, having a recess portion, formed on a substantially flat upper surface of an underlayer to partially expose the upper surface of the underlayer, a nitride-based semiconductor layer formed on the exposed part of the underlayer and the mask layer while forming a void on the recess portion of the mask layer, and a nitride-based semiconductor element layer, formed on the nitride-based semiconductor layer, having an element region. Thus, the nitride-based semiconductor layer is formed while forming the void on the recess portion of the mask layer when laterally grown on the mask layer, whereby strain of the laterally grown nitride-based semiconductor layer is so relaxed that the nitride-based semiconductor layer is improved in crystallinity. The underlayer is formed in a substantially flat shape, whereby no etching may be performed over a long time dissimilarly to a case of forming recess portions on an underlayer consisting of a nitride-based semiconductor or the like.
摘要:
A nitride-based semiconductor element having excellent element characteristics is obtained by forming a nitride-based semiconductor layer having excellent crystallinity without performing a long etching process. This nitride-based semiconductor element and the method thereof includes forming a mask layer having a recess portion on a substantially flat upper surface of an underlayer to partially expose the upper surface of the underlayer. A nitride-based semiconductor layer is laterally grown on the exposed part of the underlayer and the mask layer while forming a void on the recess portion of the mask layer. Thus, the strain of the laterally grown nitride-based semiconductor layer is so relaxed that the crystallinity of the nitride-based semiconductor layer is improved.
摘要:
A nitride-based semiconductor element having excellent element characteristics is obtained by fabricating a nitride-based semiconductor layer having excellent crystallinity without performing extended etching. The nitride-based semiconductor element comprises a mask layer, having a recess portion, formed on a substantially flat upper surface of an underlayer to partially expose the upper surface of the underlayer, a nitride-based semiconductor layer formed on the exposed part of the underlayer and the mask layer while forming a void on the recess portion of the mask layer, and a nitride-based semiconductor element layer, formed on the nitride-based semiconductor layer, having an element region. During laterally growth, strain is relaxed thereby improving crystallinity. The underlayer is formed in a substantially flat shape, thereby avoiding extended etching.
摘要:
A nitride-based semiconductor element capable of effectively preventing a nitride-based semiconductor layer of a first area from cracking and reducing the degree of warpage of a substrate is obtained. This nitride-based semiconductor element comprises a first region formed on a prescribed region of a substrate and provided with an element including a first nitride-based semiconductor layer having a prescribed thickness and a second region formed on a region of the substrate other than the first region and provided with the first nitride-based semiconductor layer with a thickness smaller than the thickness in the first region. Thus, strain easily concentrates to the second region provided with the first nitride-based semiconductor layer with the smaller thickness, whereby strain of the first region provided with the element is relaxed.
摘要:
A nitride-based semiconductor element having excellent element characteristics is obtained by obtaining a nitride-based semiconductor layer having excellent crystallinity without performing a long-time etching process. This nitride-based semiconductor element comprises a mask layer, having a recess portion, formed on a substantially flat upper surface of an underlayer to partially expose the upper surface of the underlayer, a nitride-based semiconductor layer formed on the exposed part of the underlayer and the mask layer while forming a void on the recess portion of the mask layer, and a nitride-based semiconductor element layer, formed on the nitride-based semiconductor layer, having an element region. Thus, the nitride-based semiconductor layer is formed while forming the void on the recess portion of the mask layer when laterally grown on the mask layer, whereby strain of the laterally grown nitride-based semiconductor layer is so relaxed that the nitride-based semiconductor layer is improved in crystallinity. The underlayer is formed in a substantially flat shape, whereby no etching may be performed over a long time dissimilarly to a case of forming recess portions on an underlayer consisting of a nitride-based semiconductor or the like.
摘要:
A thin nitride-based semiconductor layer having a low dislocation density is formed by laterally growing a nitride-based semiconductor layer on the upper surface of an underlayer and forming quantum dots on the laterally grown nitride-based semiconductor layer. The number of dislocations is reduced by a single lateral growth and is further reduced due to a dislocation loop effect by the quantum dots, without repeating lateral growth.
摘要:
In the manufacture of a semiconductor laser device, a low temperature buffer layer is grown on a sapphire substrate at a growth rate of 25 to 30 Å/sec. On the low temperature buffer layer, an n-GaN layer, a anti-crack layer, an n-cladding layer, an n-guide layer, an MQW active layer, a p-carrier blocking layer, a p-guide layer, a p-cladding layer and a p-contact layer are grown in this order. The growth of the low temperature buffer layer at the high growth rate allows a good low temperature buffer layer to be stably provided with good reproducibility. Thus, good crystallinity and electrical characteristics can stably be provided in the above layers.
摘要:
A semiconductor laser device capable of reducing the threshold current and improving luminous efficiency and a method of fabricating the same are obtained. This semiconductor laser device comprises a semiconductor substrate having a principal surface and a semiconductor element layer, formed on the principal surface of the semiconductor substrate, having a principal surface substantially inclined with respect to the principal surface of the semiconductor substrate and including an emission layer.