Semiconductor laser, semiconductor device and nitride series III-V group compound substrate, as well as manufacturing method thereof

Abstract

A semiconductor laser, a semiconductor device and a nitride series III-V group compound substrate capable of obtaining a crystal growth layer with less fluctuation of the crystallographic axes and capable of improving the device characteristics, as well as a manufacturing method therefor are provided. The semiconductor laser comprises, on one surface of a substrate used for growing, a plurality of spaced apart seed crystal layers and an n-side contact layer having a lateral growing region which is grown on the basis of the plurality of seed crystal layers. The seed crystal layer is formed in that a product of width w 1 (unit: μm) at the boundary thereof relative to the n-side contact layer along the arranging direction A and a thickness t 1 (unit: μm) along the direction of laminating the n-side contact layer is 15 or less. This can decrease the fluctuation of the crystallographic axes in the n-side contact layer. Accordingly, crystallinity of the semiconductor layer including from n-type clad layer to a p-side contact layer laminated on the n-side contact layer is improved. A semiconductor laser and a semiconductor device capable of decreasing dislocation density and improving device characteristics, as well as a manufacturing method therefor are provided. A semiconductor layer comprising a nitride series III-V group compound semiconductor is laminated on a substrate 11 comprising an n-type GaN. Protruded seed crystal portions are formed and a growth suppression layer having an opening corresponding to the seed crystal portion is disposed to the substrate. The semiconductor layer grows on the basis of the seed crystal portion and has a lateral growing region of low dislocation density. When a current injection region is disposed corresponding to the lateral growing region, the light emission efficiency can be improved. Further, when the growth suppression layer is provided with a function of reflecting or absorbing light generated in the semiconductor layer, it is possible to prevent leakage of light or intrusion of stray light from the substrate to suppress generation of noises.

1 - 14 . (canceled).  
     
     
         15 . A method of manufacturing a semiconductor laser including, 
 a step of growing a growth layer for seed crystal layer comprising a nitride series III-V group compound semiconductor on a substrate used for growing,    a step of selectively removing the growth layer for seed crystal layer to form a plurality of seed crystal layers and forming them in that a product between the width (unit: μm) at the upper surface on the growing side along the arranging direction thereof and a thickness (unit: μm) along the growing direction is 15 or less and    a step of growing a crystal growth layer comprising a nitride series III-V group compound semiconductor on the basis of the seed crystal layer.    
     
     
         16 . A method of manufacturing a semiconductor laser as defined in  claim 15  which includes a step of forming an injection region for injecting current to an active layer is formed corresponding to a region between the seed crystal layer and the center of the spacing region along the arranging direction thereof.  
     
     
         17 . A method of manufacturing a semiconductor laser as defined in  claim 16 , wherein the injection region of the active layer is formed corresponding to a region spaced apart from the seed crystal layer along the arranging direction thereof by (t 2 — t 1 )/20 or more and spaced apart from the center of the spacing region for the seed crystal layer along the arranging direction thereof by t 2 /20 or more where t 1  represents a thickness (unit: μm) along the growing direction of the seed crystal layer and t 2  represents a thickness (unit: μm) along the growing direction of the crystal growth layer.  
     
     
         18 . A method of manufacturing a semiconductor laser as defined in  claim 15 , wherein the crystal growth layer is grown at a rate of 6 μm/h or less.  
     
     
         19 . A method of manufacturing a semiconductor laser as defined in  claim 15 , wherein the growth layer for the seed crystal layer is selectively removed in that the spacing distance for the seed crystal layers along the arranging direction of the seed crystal layers is 9 μm or more.  
     
     
         20 . A method of manufacturing a semiconductor laser as defined in  claim 15 , wherein the method further includes a step, before the step of growing the crystal growth layer, a step of selectively removing the substrate used for growing corresponding to the removing region of the growth layer for the seed crystal layer and forming a concave portion to the substrate used for growing.  
     
     
         21 . A method of manufacturing a semiconductor device including, 
 a step of growing a growth layer for seed crystal layer comprising a nitride series III-V group compound semiconductor on a substrate used for growing,    a step of collectively removing the growth layer for seed crystal layer to form a plurality of seed crystal layers and forming them in that a product between a width (unit: μm) at the upper surface on the growing side along the arranging direction thereof and a thickness (unit: μm) along the growing direction is 15 or less and    a step of growing a crystal growth layer comprising a nitride series III-V group compound semiconductor on the basis of the seed crystal layer.    
     
     
         22 . A method of manufacturing a nitride series III-V group compound substrate including, 
 a step of growing a growth layer for seed crystal layer comprising a nitride III-V group compound semiconductor on a substrate used for growing,    a step of selectively removing the growth layer for seed crystal layer to form a plurality of seed crystal layers and forming them in that a product between a width (unit: μm) at the upper surface on a growing side along the arranging direction thereof and a thickness (unit: μm) along the growing direction is 15 or less and    a step of growing a crystal growth layer comprising a nitride series III-V group compound semiconductor on the basis of the seed crystal layer.    
     
     
         23 - 28 . (canceled).  
     
     
         29 . A method of manufacturing a semiconductor laser including 
 a step of forming a plurality of protruded seed crystal portions spaced apart from each other on a substrate comprising a nitride series III-V group compound,    a step of forming a growth suppression having an opening corresponding to the seed crystal portion of the substrate, and    a step of growing a semiconductor layer comprising a nitride series III-v group compound semiconductor on the basis of the seed crystal portion of the substrate.    
     
     
         30 . A method of manufacturing a semiconductor laser as defined by  claim 29 , wherein at least an active layer is grown as the semiconductor layer and a current injection region for injecting current to the active layer is formed corresponding to a spacing region for the seed crystal portion.  
     
     
         31 . A method of manufacturing a semiconductor laser as defined by  claim 30 , wherein the current injection region for injecting current to the active layer is formed corresponding to a region between the seed crystal portion and the center of the spacing region along the arranging direction thereof.  
     
     
         32 . A method of manufacturing a semiconductor device including 
 a step of forming a plurality of protruded seed crystal portions spaced apart from each other on a substrate comprising a nitride series III-V group compound,    a step of forming a growth suppression layer having an opening corresponding to the seed crystal portion on the substrate, and    a step of growing a semiconductor layer comprising a nitride series III-V group compound semiconductor on the basis of the seed crystal portion on the substrate.