SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME
1 Assignment
0 Petitions
Accused Products
Abstract
A semiconductor device (10) of the present invention includes: a drift layer (5) that includes a reference concentration layer (4) including an impurity of a first conductive type at a first reference concentration and a low concentration layer (3) provided under the reference concentration layer and including an impurity of the first conductive type at a concentration lower than the first reference concentration; a gate electrode (20) that is formed on an upper surface of the reference concentration layer; a pair of source regions (8a and 8b) that are respectively provided on the reference concentration layer in the vicinity of ends of the gate electrode and include an impurity of the first conductive type at a concentration higher than the first reference concentration; a pair of base regions (7a and 7b) that respectively surround outer surfaces of diffusion layers of the source regions and include an impurity of the second conductive type at a second reference concentration; a source electrode (14) that is electrically connected to the source regions and the base regions; a pair of depletion-layer extension regions (6a and 6b) that are respectively provided in the reference concentration layer under diffusion layers of the base regions and include an impurity of the second conductive type at a concentration lower than the second reference concentration; a drain layer (2) that is provided on a lower surface of the low concentration layer and includes an impurity of the first conductive type at a concentration higher than the first reference concentration; and a drain electrode (1) that is provided on a lower surface of the drain layer, a voltage being applied between the source electrode and the drain electrode. The lower surfaces of the depletion-layer extension regions are deeper than a boundary between the low concentration layer and the reference concentration layer, and intrude into the low concentration layer.
19 Citations
26 Claims
-
1-13. -13. (canceled)
-
14. A semiconductor device including a plurality of units having identical structures, each of which comprising:
-
a drain electrode; a drift layer that includes a low concentration layer on the drain electrode and a reference concentration layer on the low concentration layer, the reference concentration layer including an impurity of a first conductive type at a first concentration, and the low concentration layer including an impurity of the first conductive type at a concentration lower than the first concentration; a gate electrode on the reference concentration layer; a pair of source regions that are provided on an upper surface of the reference concentration layer and in the vicinity of both ends of the gate electrode, and include an impurity of the first conductive type at a concentration higher than the first concentration; a pair of base regions that surround outer surfaces of the source regions and include an impurity of a second conductive type at a second concentration; a source electrode electrically connected to the source regions and the base regions; and
a pair of depletion-layer extension regions that are provided under the base regions in the reference concentration layer and include an impurity of the second conductive type at a concentration lower than the second concentration, whereinfirst boundaries between the depletion-layer extension regions and the low concentration layer are positioned lower than a second boundary between the reference concentration layer and the low concentration layer. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. A method of manufacturing a semiconductor device including a plurality of units having identical structures using a semiconductor substrate that includes a drain layer including an impurity of a first conductive type at a given concentration, and a low concentration layer on the drain layer and including an impurity of the first conductive type at a concentration lower than the given concentration, the method comprising:
-
injecting an impurity of the first conductive type at a first concentration higher than that of the low concentration layer into the low concentration layer; performing a thermal treatment to make a reference concentration layer, the reference concentration layer and the low concentration layer forming a drift layer; injecting an impurity of a second conductive type into regions spaced at a given interval in the reference concentration layer to form a pair of depletion-layer extension regions; performing a thermal treatment for activating the impurity injected into the depletion-layer extension regions; forming an oxide film on the semiconductor substrate; layering a polysilicon layer on the semiconductor substrate to form a gate pattern between the depletion-layer extension regions; injecting an impurity of the second conductive type at a second concentration higher than those of the depletion-layer extension regions with the gate pattern serving as a mask for forming a pair of base regions; performing a thermal treatment to form the base regions; injecting an impurity of the first conductive type at a concentration higher than the first concentration with the gate pattern serving as a mask for forming a pair of source regions; and performing a thermal treatment to form the source regions, wherein boundaries between the depletion-layer extension regions and the low concentration layer are positioned lower than a boundary between the reference concentration layer and the low concentration layer. - View Dependent Claims (24, 25, 26)
-
Specification