US 7,601,979 B2
	Gallium nitride-based compound semiconductor multilayer structure and production method thereof
Hisayuki Miki, Ichihara (Japan); Tetsuo Sakurai, Ichihara (Japan); and Hitoshi Takeda, Ichihara (Japan)
Assigned to Showa Denko K.K., Tokyo (Japan)
Appl. No. 10/586,849 PCT Filed Jan. 28, 2005, PCT No. PCT/JP2005/001642 § 371(c)(1), (2), (4) Date Jul. 20, 2006, PCT Pub. No. WO2005/074045, PCT Pub. Date Aug. 11, 2005.
Claims priority of provisional application 60/541069, filed on Feb. 03, 2004.
Claims priority of application No. 2004-021479 (JP), filed on Jan. 29, 2004.
Prior Publication US 2007/0164296 A1, Jul. 19, 2007
Int. Cl. H01L 29/06 (2006.01)

U.S. Cl. 257—9  [257/14; 257/94; 257/103; 257/E27.135]

37 Claims

1. A gallium nitride compound semiconductor multilayer structure comprising a substrate, and an n-type layer, an active layer, and a p-type layer formed on the substrate, a negative electrode and a positive electrode being provided on the n-type layer and the p-type layer, respectively, the active layer being sandwiched by the n-type layer and the p-type layer, the active layer is a single quantum well structure formed of a single well layer or comprises at least one well layer in a multiple quantum well structure, the active layer comprising a thick portion and a thin portion, and the thick portion being disposed irregularly within a single well layer, wherein the active layer has a flat lower surface (on the substrate side) and an uneven upper surface so as to form the thick portion and the thin portion.