Semiconductor element and semiconductor light-emitting and semiconductor photoreceptor devices

• US 6,069,367 A
• Filed: 06/25/1999
• Issued: 05/30/2000
• Est. Priority Date: 06/29/1998
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Okuyama, Hiroyuki, Tsukamoto, Hironori, Taniguchi, Satoshi, Tomiya, Shigetaka, Kijima, Satoru
• Primary Examiner(s): Ngo , Ngan V.
• Application Number:
  US09/339,848
• Time in Patent Office: 340 Days
• Field of Search: 257/13, 257/15, 257/21, 257/22, 257/85, 257/96, 257/97, 257/103, 257/184, 257/201, 372/45
• US Class Current: 257/22
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 29/155 Comprising only semiconductor materials H01L29/154 takes precedence
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/28 containing only elements of Group II and Group VI of the Periodic Table
• CPC Class Codes: H01L 33/40 Materials therefor

Abstract

The purpose of the present invention is to provide a semiconductor light-emitting element that can reduce an operational voltage by improving a contact construction with a p-side electrode. An n-type clad layer, a first guide layer, an active layer, a second guide layer, a p-type clad layer, a ZnSSe cap layer, a ZnSe cap layer, a compositional gradient super-lattice layer, and a low defect contact layer are sequentially laminated on an n-type substrate. The compositional gradient super-lattice layer is formed by alternately laminating p-type ZnTe layers and p-type ZnSe layers. The p-type ZnTe layers are formed to be thickened toward the side of the low defect contact layer. The thickness of the low defect contact layer must be 5 nm or less. Relaxing lattice distortion reduces defect density of the low defect contact layer. Accordingly, the increase in the operational voltage immediately after energization is suppressed, and the operational voltage becomes lower.

Claims

1. A semiconductor element, comprising:

a first layer whose body crystal is ZnSe,

a compositional gradient super-lattice layer which is placed adjacent to the first layer, in which a ZnTe layer whose body crystal is a ZnTe and a ZnSe layer whose body crystal is ZnSe are alternately laminated more than two layers for each couple of layers, wherein the thickness of at least one of ZnTe layer and ZnSe layer varies in the direction of laminated layers to have a compositional difference, and

a second layer which is placed adjacent to the compositional gradient super-lattice layer, wherein the second layer whose body crystal is ZnTe and is 5 nm or less in thickness.

2. A semiconductor light-emitting device in which an n-type clad layer, an active layer, a p-type clad layer comprising at least one kind of II family chemical elements including zinc (Zn), magnesium (Mg), beryllium(Be), cadmium (Cd), mercury (Hg) and manganese (Mn) and at least one kind of VI family chemical elements including oxygen (O), sulfur (S), selenium (Se) and tellurium (Te) are at least sequentially laminated, and a p-side electrode is electrically connected to the p-type clad layer, the semiconductor light-emitting device comprising:

a ZnSe cap layer which is placed between the p-type clad layer and the p-side electrode and consisting of p-type ZnSe;

a compositional gradient super-lattice layer which is placed adjacent to the ZnSe cap layer and between the ZnSe cap layer and the p-side electrode, wherein the thickness of at least one of p-type ZnTe layer and p-type ZnSe layer varies in the direction of laminated layers to have a compositional slope; and

a low defect contact layer which is placed adjacent to the compositional gradient super-lattice layer and between the compositional gradient super-lattice layer and the p-side electrode, wherein the low defect contact layer consists of p-type ZnTe and is 5 nm or less in thickness.

3. A semiconductor photoreceptor device in which an n-type layer, an I layer, a p-type layer comprising at least one kind of II family chemical elements including zinc (Zn), magnesium (Mg), beryllium (Be), cadmium (Cd), mercury (Hg) and manganese (Mn) and at least one kind of VI family chemical elements including oxygen (O), sulfur (S), selenium (Se) and tellurium (Te) are at least sequentially laminated, and a p-side electrode is electrically connected to the p-type layer, comprising:

a ZnSe cap layer which is placed between the p-type layer and the p-side electrode and consisting of p-type ZnSe;

a compositional gradient super-lattice layer which is placed adjacent to the ZnSe cap layer and between the ZnSe cap layer and the p-side electrode, wherein the p-type ZnTe layer and p-type ZnSe layer are laminated alternately at least two layers for each couple of layers, and the thickness of at lease one of ZnTe layer and ZnSe layer varies in the direction of laminated layers to have a compositional difference; and

a low defect contact layer which is placed adjacent to the compositional gradient super-lattice layer and between the compositional gradient super-lattice layer and the p-side electrode, wherein the low defect contact layer consists of p-type ZnTe and is 5 nm or less in thickness.