Trench growth techniques using selective epitaxy

Semiconductor device manufacturing: process – Chemical etching – Combined with coating step

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C438S701000, C438S713000, C438S717000

Reexamination Certificate

active

06730606

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates in general to trench semiconductor devices and, more particularly, to methods of forming trenches in a semiconductor devices.
Trench semiconductor devices are used in many applications including power supplies, battery chargers, computers, and cell phones. During the process used to manufacture trench semiconductor devices a dry silicon etch step is used to form the trenches in a silicon material of the semiconductor device. However, the channel region inside the trench wall of the semiconductor device is frequently damaged and rough edges can be formed after the dry silicon etch step. The damage to the channel region can cause leakage which then causes reduced carrier lifetime in the channel area. Decreased carrier lifetime increases the voltage threshold thereby increasing the on-state resistance of the semiconductor device. There is conventional prior art cleaning processes used to reduce the damage to the trench wall of the semiconductor device, but is at the cost of extra process steps. However, the extra process steps used to remove the damage to the trench walls frequently does not completely anneal the trench walls leaving the damage to the channel region in the semiconductor device.
Furthermore, the trench depth of a semiconductor device is typically a critical dimension which is difficult to meet using the dry silicon etch process. or example, a trench power MOSFET device should have the trench depth just below the diffused body region to minimize the gate to drain capacitance and minimize the gate oxide electric field strength.
Accordingly, it is desirable to have a manufacturing process to form trenches in a semiconductor device without causing damage to the trench. Further, it is desirable to have the manufacturing process provide an accurate alignment of the trench bottom to specific dopant distribution during the process steps. The invention disclosed herein will address the above problems.


REFERENCES:
patent: 5013680 (1991-05-01), Lowrey et al.
patent: 6150708 (2000-11-01), Gardner et al.
patent: 6239463 (2001-05-01), Williams et al.
patent: 6291298 (2001-09-01), Williams et al.
patent: 2001/0049167 (2001-12-01), Madson

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Trench growth techniques using selective epitaxy does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Trench growth techniques using selective epitaxy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Trench growth techniques using selective epitaxy will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3263171

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.