US 11,952,676 B2
Silicon carbide crystal
Ching-Shan Lin, Hsinchu (TW); Jian-Hsin Lu, Hsinchu (TW); Chien-Cheng Liou, Hsinchu (TW); and Man-Hsuan Lin, Hsinchu (TW)
Assigned to GLOBALWAFERS CO., LTD., Hsinchu (TW)
Filed by GlobalWafers Co., Ltd., Hsinchu (TW)
Filed on Oct. 16, 2020, as Appl. No. 17/072,973.
Application 17/072,973 is a division of application No. 15/941,129, filed on Mar. 30, 2018, granted, now 10,851,470.
Claims priority of application No. 106134548 (TW), filed on Oct. 6, 2017.
Prior Publication US 2021/0054525 A1, Feb. 25, 2021
Int. Cl. H01L 29/16 (2006.01); C30B 23/00 (2006.01); C30B 23/02 (2006.01); C30B 25/02 (2006.01); C30B 29/36 (2006.01); H01L 21/02 (2006.01); H01L 29/32 (2006.01); H01L 29/36 (2006.01)
CPC C30B 23/025 (2013.01) [C30B 23/005 (2013.01); C30B 25/02 (2013.01); C30B 29/36 (2013.01); H01L 21/02378 (2013.01); H01L 21/02447 (2013.01); H01L 21/02507 (2013.01); H01L 21/0251 (2013.01); H01L 21/02529 (2013.01); H01L 21/02576 (2013.01); H01L 21/02631 (2013.01); H01L 29/1608 (2013.01); H01L 29/32 (2013.01); H01L 29/36 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A silicon carbide crystal, comprising a seed layer, a bulk layer, and a stress buffering structure formed between the seed layer and the bulk layer, wherein the seed layer, the bulk layer, and the stress buffering structure are each formed with a dopant having a concentration, and the concentration of the dopant of the stress buffering structure cycles between high and low dopant concentrations in a thickness direction of the stress buffering structure;
characterized in that the stress buffering structure includes a plurality of stacked buffer layers and a transition layer over the buffer layers, wherein the buffer layer closest to the seed layer has the same variation trend of the concentration of the dopant as the buffer layer closest to the transition layer, and the concentration of the dopant of the transition layer is equal to the concentration of the dopant of the seed layer;
wherein the dopant of the seed layer has a reference concentration, and the concentration of the dopant of each of the buffer layers gradually increases or decreases between the reference concentration and a first concentration higher than the reference concentration in the thickness direction.