Nitride-based semiconductor light-emitting element and manufacturing method thereof, and manufacturing method of nitride-based semiconductor crystal

Abstract

A manufacturing method of a nitride-based semiconductor light-emitting element includes: forming an n-type nitride-based semiconductor layer; forming, on the n-type nitride-based semiconductor layer, a light emission layer including a nitride-based semiconductor; forming, on the light emission layer in an atmosphere containing a hydrogen gas, a p-type nitride-based semiconductor layer while doping the p-type nitride-based semiconductor layer with a p-type dopant at a concentration of at least 2.0×1018 atom/cm3; and annealing the p-type nitride-based semiconductor layer at a temperature of at least 800 degrees Celsius in an atmosphere not containing hydrogen. In this manufacturing method, a hydrogen concentration of the p-type nitride-based semiconductor layer after the annealing is at most 5.0×1018 atom/cm3 and at most 5% of the concentration of the p-type dopant, and a hydrogen concentration of the light emission layer is at most 2.0×1017 atom/cm3.

1 . A manufacturing method of a nitride-based semiconductor light-emitting element, the manufacturing method comprising:
 forming an n-type nitride-based semiconductor layer;   forming, on the n-type nitride-based semiconductor layer, a light emission layer including a nitride-based semiconductor;   forming, on the light emission layer in an atmosphere containing a hydrogen gas, a p-type nitride-based semiconductor layer while doping the p-type nitride-based semiconductor layer with a p-type dopant at a concentration of at least 2.0×10 18  atom/cm 3 ; and   annealing the p-type nitride-based semiconductor layer at a temperature of at least 800 degrees Celsius in an atmosphere not containing hydrogen,   wherein a hydrogen concentration of the p-type nitride-based semiconductor layer after the annealing is at most 5.0×10 18  atom/cm 3  and at most 5% of the concentration of the p-type dopant, and   a hydrogen concentration of the light emission layer is at most 2.0×10 17  atom/cm 3 .   
     
     
         2 . The manufacturing method according to  claim 1 , wherein
 the annealing includes:   first annealing of annealing the p-type nitride-based semiconductor layer at a temperature of at least 800 degrees Celsius in an inert gas atmosphere; and   second annealing of annealing the p-type nitride-based semiconductor layer at a temperature of at most 800 degrees Celsius in an oxidizing gas atmosphere after the first annealing.   
     
     
         3 . The manufacturing method according to  claim 2 , further comprising:
 forming a ridge by removing part of the p-type nitride-based semiconductor layer,   wherein the forming of the ridge is performed after the first annealing, before the second annealing.   
     
     
         4 . The manufacturing method according to  claim 1 , further comprising:
 forming, on the p-type nitride-based semiconductor layer, an oxide selected from a group consisting of tantalum, vanadium, tin, indium, molybdenum, tungsten, niobium, titanium, cobalt, manganese, yttrium, and silicon.   
     
     
         5 . A manufacturing method of a nitride-based semiconductor crystal, the manufacturing method comprising:
 forming, in an atmosphere containing a hydrogen gas, a p-type nitride-based semiconductor crystal while doping the p-type nitride-based semiconductor layer with a p-type dopant at a concentration of at least 2.0×10 18  atom/cm 3 ;   first annealing of annealing the p-type nitride-based semiconductor crystal at a temperature of at least 800 degrees Celsius in an inert gas atmosphere; and   second annealing of annealing the p-type nitride-based semiconductor crystal at a temperature of at most 800 degrees Celsius in an oxidizing gas atmosphere after the first annealing,   wherein a hydrogen concentration of the p-type nitride-based semiconductor crystal after the second annealing is at most 5.0×10 18  atom/cm 3  and at most 5% of the concentration of the p-type dopant.   
     
     
         6 . A nitride-based semiconductor light-emitting element, comprising:
 an n-type nitride-based semiconductor layer;   a light emission layer including a nitride-based semiconductor; and   a p-type nitride-based semiconductor layer,   wherein the n-type nitride-based semiconductor layer, the light emission layer, and the p-type nitride-based semiconductor layer are laminated in sequence,   a concentration of a p-type dopant of the p-type nitride-based semiconductor layer is at least 2.0×10 18  atom/cm 3 ,   a hydrogen concentration of the p-type nitride-based semiconductor layer is at most 5.0×10 18  atom/cm 3  and at most 5% of the concentration of the p-type dopant,   an oxygen concentration of the p-type nitride-based semiconductor layer is higher than an oxygen concentration of the light emission layer, and   a hydrogen concentration of the light emission layer is at most 2.0×10 17  atom/cm 3 .   
     
     
         7 . The nitride-based semiconductor light-emitting element according to  claim 6 , wherein
 the p-type nitride-based semiconductor layer contains aluminum.   
     
     
         8 . The nitride-based semiconductor light-emitting element according to  claim 6 , further comprising:
 an oxide selected from a group consisting of tantalum, vanadium, tin, indium, molybdenum, tungsten, niobium, titanium, cobalt, manganese, yttrium, and silicon, the oxide being provided on the p-type nitride-based semiconductor layer.   
     
     
         9 . A nitride-based semiconductor light-emitting element, comprising:
 an n-type nitride-based semiconductor layer;   a light emission layer including a nitride-based semiconductor; and   a p-type nitride-based semiconductor layer,   wherein the n-type nitride-based semiconductor layer, the light emission layer, and the p-type nitride-based semiconductor layer are laminated in sequence,   a concentration of a p-type dopant of the p-type nitride-based semiconductor layer is at least 2.0×10 18  atom/cm 3 , and   a hydrogen concentration of the p-type nitride-based semiconductor layer is at most 5.0×10 18  atom/cm 3  and at most 5% of the concentration of the p-type dopant,   the nitride-based semiconductor light-emitting element further comprising:   an oxide selected from a group consisting of tantalum, vanadium, tin, indium, molybdenum, tungsten, niobium, titanium, cobalt, manganese, yttrium, and silicon, the oxide being provided on the p-type nitride-based semiconductor layer.   
     
     
         10 . The nitride-based semiconductor light-emitting element according to  claim 9 , wherein
 a hydrogen concentration of the light emission layer is at most 2.0×10 17  atom/cm 3 .   
     
     
         11 . The nitride-based semiconductor light-emitting element according to  claim 6 , wherein
 the light emission layer contains indium.   
     
     
         12 . The nitride-based semiconductor light-emitting element according to  claim 6 , further comprising:
 an undoped nitride-based semiconductor layer provided between the light emission layer and the p-type nitride-based semiconductor layer.   
     
     
         13 . A nitride-based semiconductor light-emitting element, comprising:
 an n-type nitride-based semiconductor layer;   a light emission layer including a nitride-based semiconductor; and   a p-type nitride-based semiconductor layer,   wherein the n-type nitride-based semiconductor layer, the light emission layer, and the p-type nitride-based semiconductor layer are laminated in sequence, and   a hydrogen concentration of the light emission layer is at most 2.0×10 17  atom/cm 3 ,   the nitride-based semiconductor light-emitting element further comprising:   an oxide selected from a group consisting of tantalum, vanadium, tin, indium, molybdenum, tungsten, niobium, titanium, cobalt, manganese, yttrium, and silicon, the oxide being provided on the p-type nitride-based semiconductor layer.   
     
     
         14 . The nitride-based semiconductor light-emitting element according to  claim 13 , wherein
 the oxide is an electrically-conductive translucent material.   
     
     
         15 . The nitride-based semiconductor light-emitting element according to  claim 13 , wherein
 an oxygen concentration of the p-type nitride-based semiconductor layer is higher than an oxygen concentration of the light emission layer.   
     
     
         16 . The nitride-based semiconductor light-emitting element according to  claim 13 , wherein
 the nitride-based semiconductor light-emitting element is a semiconductor laser element having an oscillation wavelength band of at least 365 nm and at most 390 nm and light output of at least 1 W.   
     
     
         17 . The nitride-based semiconductor light-emitting element according to  claim 13 , wherein
 the nitride-based semiconductor light-emitting element is a semiconductor laser element having an oscillation wavelength band of at least 390 nm and at most 420 nm and light output of at least 3 W.   
     
     
         18 . The nitride-based semiconductor light-emitting element according to  claim 13 , wherein
 the nitride-based semiconductor light-emitting element is a semiconductor laser element having an oscillation wavelength band of at least 420 nm and at most 460 nm and light output of at least 6 W.   
     
     
         19 . The nitride-based semiconductor light-emitting element according to  claim 13 , wherein
 the nitride-based semiconductor light-emitting element is a semiconductor laser element having a resonator length of at least 1300 μm.   
     
     
         20 . The nitride-based semiconductor light-emitting element according to  claim 13 , wherein
 the nitride-based semiconductor light-emitting element is a semiconductor laser element having a stripe width of at least 50 μm.