US 11,721,752 B2
Semiconductor device having doped seed layer and method of manufacturing the same
Chi-Ming Chen, Zhubei (TW); Po-Chun Liu, Hsinchu (TW); Chung-Yi Yu, Hsinchu (TW); Chia-Shiung Tsai, Hsinchu (TW); and Ru-Liang Lee, Hsinchu (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD., Hsinchu (TW)
Filed by TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD., Hsinchu (TW)
Filed on Oct. 20, 2020, as Appl. No. 17/74,952.
Application 17/074,952 is a continuation of application No. 16/687,219, filed on Nov. 18, 2019, granted, now 11,329,148.
Application 16/687,219 is a continuation of application No. 14/158,157, filed on Jan. 17, 2014, granted, now 10,483,386, issued on Nov. 19, 2019.
Prior Publication US 2021/0036140 A1, Feb. 4, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 29/778 (2006.01); H01L 29/20 (2006.01); H01L 29/66 (2006.01); H01L 21/02 (2006.01); H01L 21/265 (2006.01)
CPC H01L 29/7787 (2013.01) [H01L 21/0251 (2013.01); H01L 21/0254 (2013.01); H01L 21/0262 (2013.01); H01L 21/02458 (2013.01); H01L 21/02579 (2013.01); H01L 29/2003 (2013.01); H01L 29/66462 (2013.01); H01L 21/26546 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A semiconductor device comprising:
a doped substrate;
a seed layer in direct contact with the substrate, wherein the seed layer comprises:
a first seed sublayer having a first lattice structure, wherein the first seed sublayer comprises AlN, and the first seed sublayer is doped with carbon, and
a second seed sublayer over the first seed layer, wherein the second seed layer has a second lattice structure different from the first lattice structure, and a thickness of the second seed sublayer ranges from about 50 nanometers (nm) to about 200 nm;
a graded layer in direct contact with the seed layer, wherein the graded layer comprises:
a first graded sublayer including AlGaN, wherein the first graded sublayer has a first Al:Ga ratio;
a second graded sublayer over the first graded sublayer, wherein the second graded sublayer includes AlGaN, and the second graded sublayer has a second Al:Ga ratio different from the first Al:Ga ratio; and
a third graded sublayer over the second graded sublayer, wherein the third graded sub layer includes AlGaN, and the third graded sublayer has a third Al:Ga ratio different from the second Al:Ga ratio;
a channel layer over the graded layer, wherein a two-dimensional electron gas (2-DEG) is defined in the channel layer; and
an active layer over the channel layer.