Manufacturing a Semiconductor Device Using Electrochemical Etching, Semiconductor Device and Super Junction Semiconductor Device
First Claim
1. A method of manufacturing a semiconductor device, the method comprising:
- forming a trench in a semiconductor substrate between mesas of a first conductivity type, the trench extending from a process surface down to a bottom plane;
forming a semiconductor layer of a second, complementary conductivity type on sidewalls of the trench, wherein at least in the mesas a vertical impurity concentration profile vertical to the process surface is non-constant between the process surface and the bottom plane; and
thereafterremoving a portion of the semiconductor layer in the trench by electrochemical etching.
1 Assignment
0 Petitions
Accused Products
Abstract
A trench is formed in a semiconductor substrate between mesas of a first conductivity type. The trench extends from a process surface down to a bottom plane. A semiconductor layer of a second, complementary conductivity type is formed on sidewalls of the trench. At least in the mesas a vertical impurity concentration profile vertical to the process surface is non-constant between the process surface and the bottom plane. A portion of the semiconductor layer in the trench is removed by electrochemical etching. Thereafter, the thickness of the recessed semiconductor layer images the vertical impurity concentration profile in the mesa.
-
Citations
20 Claims
-
1. A method of manufacturing a semiconductor device, the method comprising:
-
forming a trench in a semiconductor substrate between mesas of a first conductivity type, the trench extending from a process surface down to a bottom plane; forming a semiconductor layer of a second, complementary conductivity type on sidewalls of the trench, wherein at least in the mesas a vertical impurity concentration profile vertical to the process surface is non-constant between the process surface and the bottom plane; and
thereafterremoving a portion of the semiconductor layer in the trench by electrochemical etching. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A semiconductor device, comprising:
-
semiconductor mesas of a first conductivity type extending between a first surface and a bottom plane of a semiconductor portion; and a semiconductor structure of a second, complementary conductivity type extending along sidewalls of the semiconductor mesas, wherein a thickness of the semiconductor structure has a local maximum value at a first distance to both the first surface and the bottom plane, and a vertical impurity concentration profile in the semiconductor portion has a local maximum at the first distance to the first surface. - View Dependent Claims (13, 14, 15)
-
-
16. (canceled)
-
17. A super junction semiconductor device, comprising:
-
a semiconductor portion comprising a subsurface structure extending from a first surface of the semiconductor portion between mesas down to a bottom plane, wherein the mesas have a first conductivity type and the subsurface structure comprises semiconductor structures of a second, complementary conductivity type extending along sidewalls of the mesas, wherein a thickness of the semiconductor structures has a local maximum at a first distance to the first surface, the first distance being smaller than a main distance between the first surface and the bottom plane, and wherein the super junction semiconductor device is a vertical insulated gate field effect transistor including a first load electrode and a control terminal at a first side of the semiconductor portion and a second load electrode at a second side of the semiconductor portion opposite to the first side. - View Dependent Claims (18, 19)
-
-
20. (canceled)
Specification