US2021151314A1PendingUtilityA1

Method for manufacturing group iii nitride semiconductor substrate

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Assignee: SUMCO CORPPriority: Dec 19, 2017Filed: Oct 2, 2018Published: May 20, 2021
Est. expiryDec 19, 2037(~11.4 yrs left)· nominal 20-yr term from priority
Inventors:Koji MatsumotoToshiaki OnoHiroshi AmanoYoshio Honda
H10P 14/38H10P 36/03H10P 14/3416H10P 14/3251H10P 14/3248H10P 14/3216H10P 14/2926H10P 14/24H10P 14/2905C30B 29/403C30B 25/183C23C 16/52C23C 16/46C23C 16/303C23C 16/0281C30B 29/38C30B 25/16C23C 16/34H01L 21/02664H01L 21/02381H01L 21/02505H01L 21/02458H01L 21/205H01L 21/3221H01L 21/0254H10P 95/402
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Claims

Abstract

Diffusion of a group III material into an Si substrate is suppressed during the time when a group III nitride semiconductor layer is grown on the Si substrate, with an AlN buffer layer being interposed therebetween. A method for manufacturing a group III nitride semiconductor substrate comprises: a step for growing a first AlN buffer layer on an Si substrate; a step for growing a second AlN buffer layer on the first AlN buffer layer at a temperature higher than a growth temperature of the first AlN buffer layer; and a step for growing a group III nitride semiconductor layer on the second AlN buffer layer. The growth temperature of the first AlN buffer layer is 400-600° C.

Claims

exact text as granted — not AI-modified
1 . A method for manufacturing a group III nitride semiconductor substrate comprising steps of:
 growing a first AlN buffer layer on an Si substrate;   growing a second AlN buffer layer on the first AlN buffer layer at a temperature higher than a growth temperature of the first AlN buffer layer; and   growing a group III nitride semiconductor layer on the second AlN buffer layer, wherein   the growth temperature of the first AlN buffer layer is 400° C. to 600° C.   
     
     
         2 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 1 , wherein a growth temperature of the second AlN buffer layer is 900° C. to 1200° C. 
     
     
         3 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 1 , wherein the thickness of the first AlN buffer layer is 0.4 nm to 100 nm. 
     
     
         4 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 1 , wherein a total thickness of the first and second AlN buffer layers is 30 nm to 200 nm. 
     
     
         5 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 1 , wherein
 the step of growing the group III nitride semiconductor layer includes steps of:   growing a first group III nitride semiconductor layer on the second AlN buffer layer; and   growing a second group III nitride semiconductor layer on the first group III nitride semiconductor layer at a temperature higher than a growth temperature of the first group III nitride semiconductor layer, wherein   the growth temperature of the first group III nitride semiconductor layer is 400° C. to 800° C., and   the growth temperature of the first AlN buffer layer is lower than the growth temperature of the first group III nitride semiconductor layer.   
     
     
         6 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 1 , wherein a resistivity of the Si substrate is 100 Ωcm or more, the Si substrate contains an impurity element selected from C, Ge, Sn, O, H, and a group V element, and the concentration of the impurity element contained at least in a surface layer part of the Si substrate ranging from the surface to the depth of 0.5 um to 10 um is 1×10 12  atoms/cm 3  to 1×10 20  atoms/cm 3 . 
     
     
         7 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 1  further includes, before growing the group III nitride semiconductor layer, a step of applying heat treatment at 900° C. to 1450° C. to the Si substrate on which the first AlN buffer layer and second AlN buffer layer have been sequentially grown. 
     
     
         8 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 1 , wherein the Si substrate has a main surface inclined toward a <112> direction by 0.1° to 1.5° from the (111) plane of a silicon single crystal. 
     
     
         9 . A method for manufacturing a group III nitride semiconductor substrate comprising steps of:
 growing a first AlN buffer layer on an Si substrate at a first growth temperature;   growing a second AlN buffer layer on the first AlN buffer layer at a second growth temperature higher than the first growth temperature; and   growing a group III nitride semiconductor layer on the second AlN buffer layer,   wherein an Al raw material and an N raw material are alternately repeatedly fed in the step of growing the first AlN buffer layer.   
     
     
         10 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 9 , wherein the first growth temperature is 400° C. to 800° C., and the second growth temperature is 900° C. to 1200° C. 
     
     
         11 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 10 , wherein the first growth temperature is 400° C. to 600° C. 
     
     
         12 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 9 , wherein the Al raw material is introduced prior to the introduction of the N raw material in the step of growing the first AlN buffer layer. 
     
     
         13 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 9 , wherein the thickness of the first AlN buffer layer is 0.4 nm to 100 nm. 
     
     
         14 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 9 , wherein a total thickness of the first and second AlN buffer layers is 30 nm to 200 nm. 
     
     
         15 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 9 , wherein the Al raw material and the N raw material are each fed for 0.5 seconds to 10 seconds in the step of growing the first AlN buffer layer. 
     
     
         16 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 9 , wherein the Al raw material and the N raw material are alternately repeatedly fed in the step of growing the second AlN buffer layer. 
     
     
         17 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 9  further comprising a step of applying heat treatment at 900° C. to 1450° C. to the Si substrate on which the first AlN buffer layer and second AlN buffer layer have been sequentially grown before growing the group III nitride semiconductor layer. 
     
     
         18 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 9 , wherein the Si substrate has a main surface inclined toward a <112> direction by 0.1° to 1.5° from the (111) plane of a silicon single crystal. 
     
     
         19 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 9 , wherein
 the step of growing the group III nitride semiconductor layer includes steps of:   growing a first group III nitride semiconductor layer on the second AlN buffer layer at a third growth temperature; and   growing a second group III nitride semiconductor layer on the first group III nitride semiconductor layer at a fourth growth temperature higher than the third growth temperature.   
     
     
         20 . The method for manufacturing a group III nitride semiconductor method as claimed in  claim 19 , wherein the third growth temperature is 400° C. to 800° C., and the fourth growth temperature is 900° C. to 1200° C. 
     
     
         21 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 19 , wherein the thickness of the first group III nitride semiconductor layer is 10 nm to 200 nm. 
     
     
         22 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 19 , wherein a group III raw material and the N raw material are alternately repeatedly fed in the step of growing the first group III nitride semiconductor layer. 
     
     
         23 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 19 , wherein
 the first group III nitride semiconductor layer is made of AlGaN, and   the second group III nitride semiconductor layer is made of GaN.   
     
     
         24 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 9 , wherein a resistivity of the Si substrate is 100 Ωcm or more, the Si substrate contains an impurity element selected from C, Ge, Sn, O, H, and a group V element, and the concentration of the impurity element contained at least in a surface layer part of the Si substrate ranging from the surface to the depth of 0.5 um to 10 um is 1×10 12  atoms/cm 3  to 1×10 20  atoms/cm 3 . 
     
     
         25 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 24 , wherein the concentration of the impurity element contained in the entire Si substrate including the surface layer part is 1×10 12  atoms/cm 3  to 1×10 20  atoms/cm 3 . 
     
     
         26 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 24 , wherein the concentration of impurity element contained in a deeper area than the surface layer part is lower than the concentration in the surface layer part. 
     
     
         27 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 24 , wherein the impurity element is C, and the concentration of the impurity element contained in the surface layer part is 1×10 14  atoms/cm 3  to 1×10 17  atoms/cm 3 . 
     
     
         28 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 24 , wherein the impurity element is Ge or Sn, and the concentration of the impurity element contained in the surface layer part is 1×10 14  atoms/cm 3  to 1×10 20  atoms/cm 3 . 
     
     
         29 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 24 , wherein the impurity element is O, and the concentration of the impurity element contained in the surface layer part is 1×10 15  atoms/cm 3  to 5×10 18  atoms/cm 3 . 
     
     
         30 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 24 , wherein the impurity element is H, and the concentration of the impurity element contained in the surface layer part is 1×10 15  atoms/cm 3  to 5×10 18  atoms/cm 3 . 
     
     
         31 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 26 , wherein the impurity element contains at least one group V element selected from N, P, As, and Sb, the concentration of the impurity element contained in the surface layer part is 1×10 12  atoms/cm 3  to 1×10 19  atoms/cm 3 , and the concentration of the impurity element contained in a deeper area than the surface layer part is 1×10 14  atoms/cm 3  or less. 
     
     
         32 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 31 , wherein the impurity element in the Si substrate has a concentration gradient in which the concentration thereof is reduced toward the substrate interior from the surface. 
     
     
         33 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 9 , wherein
 a raw material containing a group V element (P, As, Sb) other than N is fed together with the Al raw material or N raw material in the step of growing the first AlN buffer layer.   
     
     
         34 . A method for manufacturing a group III nitride semiconductor substrate comprising steps of:
 growing an AlN buffer layer on an Si substrate at a growth temperature of 900° C. to 1200° C.; and   growing a group III nitride semiconductor layer on the AlN buffer layer, wherein   a resistivity of the Si substrate is 100 Ωcm or more,   the Si substrate contains an impurity element selected from C, Ge, Sn, O, and H, and   the concentration of the impurity element contained at least in a surface layer part of the Si substrate ranging from the surface to the depth of 0.5 um to 10 um is 1×10 14  atoms/cm 3  to 1×10 20  atoms/cm 3 .   
     
     
         35 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 34 , wherein the concentration of the impurity element contained in the entire Si substrate including the surface layer part is 1×10 12  atoms/cm 3  to 1×10 20  atoms/cm 3 . 
     
     
         36 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 34 , wherein the concentration of impurity element contained in a deeper area than the surface layer part is lower than the concentration in the surface layer part. 
     
     
         37 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 34 , wherein the impurity element is C, and the concentration of the impurity element contained in the surface layer part is 1×10 14  atoms/cm 3  to 1×10 17  atoms/cm 3 . 
     
     
         38 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 34 , wherein the impurity element is Ge or Sn, and the concentration of the impurity element contained in the surface layer part is 1×10 14  atoms/cm 3  to 1×10 20  atoms/cm 3 . 
     
     
         39 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 34 , wherein the impurity element is O, and the concentration of the impurity element contained in the surface layer part is 1×10 15  atoms/cm 3  to 5×10 18  atoms/cm 3 . 
     
     
         40 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 34 , wherein the impurity element is H, and the concentration of the impurity element contained in the surface layer part is 1×10 15  atoms/cm 3  to 5×10 18  atoms/cm 3 . 
     
     
         41 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 36 , wherein the impurity element contains at least one group V element selected from N, P, As, and Sb, the concentration of the impurity element contained in the surface layer part is 1×10 12  atoms/cm 3  to 1×10 19  atoms/cm 3 , and the concentration of the impurity element contained in a deeper area than the surface layer part is 1×10 14  atoms/cm 3  or less. 
     
     
         42 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 41 , wherein the impurity element in the Si substrate has a concentration gradient in which the concentration thereof is reduced toward the substrate interior from the surface. 
     
     
         43 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 34 , wherein a step of applying heat treatment at 900° C. to 1450° C. to the Si substrate on which the AN buffer layer has been grown before growing the group III nitride semiconductor layer. 
     
     
         44 . The method for manufacturing a group III nitride semiconductor substrate as claimed in  claim 34 , wherein the Si substrate has a main surface inclined toward a <112> direction by 0.1° to 1.5° from the (111) plane of a silicon single crystal. 
     
     
         45 . A method for manufacturing a group III nitride semiconductor substrate comprising steps of:
 growing an AlN buffer layer on an Si substrate;   applying heat treatment at 900° C. to 1450° C. to the Si substrate on which the AN buffer layer has been grown; and   growing a group III nitride semiconductor layer on the AlN buffer layer that has been subjected to the heat treatment.   
     
     
         46 . A method for manufacturing a group III nitride semiconductor substrate comprising steps of:
 growing an AlN buffer layer on an Si substrate; and   growing a group III nitride semiconductor layer on the AlN buffer layer, wherein   the Si substrate has a main surface inclined toward a <112> direction by 0.1° to 1.5° from the (111) plane of a silicon single crystal.

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