US 7,321,158 B2
Method of manufacturing variable capacitance diode and variable capacitance diode
Yutaka Nabeshima, Osaka (Japan)
Assigned to Matsushita Electric Industrial Co., Ltd., Osaka (Japan)
Filed on Dec. 15, 2004, as Appl. No. 11/11,037.
Claims priority of application No. P2003-416209 (JP), filed on Dec. 15, 2003; and application No. P2004-110683 (JP), filed on Apr. 05, 2004.
Prior Publication US 2005/0148149 A1, Jul. 07, 2005
Int. Cl. H01L 29/00 (2006.01)
U.S. Cl. 257—499 6 Claims
OG exemplary drawing
 
1. A variable capacitance diode, comprising:
a semiconductor substrate and a plurality of units disposed in an array on the semiconductor substrate, each of the units including:
a first semiconductor region of a first conductive type having a low impurity concentration;
a second semiconductor region of the first conductive type having an intermediate impurity concentration;
a third semiconductor region of a second conductive type having a high impurity concentration; and
an annular contact layer of the first conductive type in the periphery of the third semiconductor region, wherein a side surface of the third semiconductor region is connected to the first semiconductor region, and a bottom surface of the third semiconductor region is connected to the second semiconductor region.