US 11,705,489 B2
Buffer layer structure to improve GaN semiconductors
Jia-Zhe Liu, Hsinchu (TW); Yen Lun Huang, Hsinchu (TW); Chih-Yuan Chuang, Hsinchu (TW); Che Ming Liu, Hsinchu (TW); Wen-Ching Hsu, Hsinchu (TW); and Manhsuan Lin, Hsinchu (TW)
Assigned to GlobalWafers Co., Ltd., Hsinchu (TW)
Filed by GlobalWafers Co., Ltd., Hsinchu (TW)
Filed on Dec. 19, 2018, as Appl. No. 16/226,265.
Claims priority of provisional application 62/617,484, filed on Jan. 15, 2018.
Prior Publication US 2019/0221648 A1, Jul. 18, 2019
Int. Cl. H01L 29/205 (2006.01); H01L 29/20 (2006.01); H01L 21/02 (2006.01)
CPC H01L 29/205 (2013.01) [H01L 21/02458 (2013.01); H01L 21/02505 (2013.01); H01L 29/2003 (2013.01); H01L 21/0251 (2013.01); H01L 21/0262 (2013.01); H01L 21/02507 (2013.01); H01L 21/02538 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A heterostructure, comprising:
a substrate; and
a buffer layer comprising a plurality of layers having a composition AlInGaN;
wherein the buffer layer has a first region, comprising at least two layers, one according to a first layer profile and another according to a second layer profile, wherein the first layer profile has a higher aluminum content than the second layer profile;
wherein the buffer layer has a second region comprising at least two layers, one according to a third layer profile and another according to a fourth layer profile, wherein the third layer profile has a higher aluminum content than the fourth layer profile and the fourth layer profile has a lower aluminum content than the second layer profile of the first region;
wherein the buffer layer has a third region comprising at least two layers, one according to a fifth layer profile and another according to a sixth layer profile, wherein the fifth layer profile has a higher aluminum content than the sixth layer profile and the sixth layer profile has a lower aluminum content than the fourth layer profile of the second region;
wherein the first region, the second region, and the third region are ordered consecutively;
wherein each individual layer independently has a thickness, measured in a growth direction, between about 1 nanometer and 50 nanometers;
wherein the aluminum content in the odd numbered layers is between 0.91 and 1;
wherein the aluminum content in the second layer profile is between 0.51 and 0.9;
wherein the aluminum content in the fourth layer profile is between 0.26 and 0.5;
wherein the aluminum content in the sixth layer profile is between 0.01 and 0.25; and
wherein the first layer profile and second layer profile repeat at least three time within the first region, the third layer profile and fourth layer profile repeat at least three time within the second region, or the fifth layer profile and sixth layer profile repeat at least three times within the third region.