EP0395330A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of forming an oxide liner and active area mask for selective epitaxial growth in an isolation trench
Assignee: Motorola Solutions Inc
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Filing: 1990-04-23
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Granted: —
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Expires: 2010-04-23
Abstract
Abstract A new method is used to fabricate an isolation trench to prevent spurious epitaxial growth at the top edge of the trench opening and at pin holes in oxide over the active area. The method involves etching a deep trench into a semiconductor wafer that is patterned with a mask oxide layer, and then depositing a low temperature oxide, followed by growing a thermal oxide layer under the mask oxide and in the trench. When the oxide at the bottom of the trench is removed to provide a seed for the growth of selective epitaxial silicon, an oxide layer thick enough to leave a protective coating over the active area and at the trench opening is provided which prevents spurious epitaxial silicon growth.
Inventors
- 👤 Frederick J. Robinson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 19:00
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/041; H10W10/40; H10W20/00; H10W20/01; H10W20/021
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
166 words
A method of fabricating a trench isolation 5 structure, comprising the steps of: providing a semiconductor substrate (10) having a surface; providing a mask (11) made of an oxide layer disposed on the semiconductor substrate (10); removing portions of the mask (11) to provide at least one opening to the semiconductor substrate (10); removing portions of the substrate (10) through the mask (11) opening to form a trench (12) in the substrate (10), wherein the trench (12) is at least approximately 10 microns in depth from the surface of the substrate (10); depositing a first oxide layer (13) such that the first oxide layer (13) is thicker on the mask (11) than in the trench (12); growing a second oxide layer (14) to densify and level out the first oxide layer (13); and removing the first and second oxide layers (13 and 14) at the bottom of the trench (12) and removing a portion of the first oxide layer (13) at the surface of the substrate.
Claim 2
Independent Claim
166 words
A method of fabricating a trench isolation 5 structure, comprising the steps of: providing a semiconductor substrate (10) having a surface; providing a mask (11) made of an oxide layer disposed on the semiconductor substrate (10); removing portions of the mask (11) to provide at least one opening to the semiconductor substrate (10); removing portions of the substrate (10) through the mask (11) opening to form a trench (12) in the substrate (10), wherein the trench (12) is at least approximately 10 microns in depth from the surface of the substrate (10); depositing a first oxide layer (13) such that the first oxide layer (13) is thicker on the mask (11) than in the trench (12); growing a second oxide layer (14) to densify and level out the first oxide layer (13); and removing the first and second oxide layers (13 and 14) at the bottom of the trench (12) and removing a portion of the first oxide layer (13) at the surface of the substrate.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein the first oxide layer (13) is a low temperature oxide, and the second oxide layer (14) is a thermal oxide layer.
Claim 4
Independent Claim
117 words
A method of fabricating a trench isolation structure, comprising the steps of: providing a trench (12) of at least 10 microns in depth in a semiconductor substrate (10), formed by etching the substrate (10) through an oxide mask opening (11); depositing a first oxide layer (13) so that the first oxide layer (13) is thicker on the mask oxide (11) than on the trench (12) sidewalls; growing a second oxide layer (14) to densify and to level out the first oxide layer (13); and removing a portion of the first oxide layer (13) from the substrate (10) surface and removing the first and second oxide a seed for growing a selective semiconductor layer in the trench (12).
Claim 5
Independent Claim
117 words
A method of fabricating a trench isolation structure, comprising the steps of: providing a trench (12) of at least 10 microns in depth in a semiconductor substrate (10), formed by etching the substrate (10) through an oxide mask opening (11); depositing a first oxide layer (13) so that the first oxide layer (13) is thicker on the mask oxide (11) than on the trench (12) sidewalls; growing a second oxide layer (14) to densify and to level out the first oxide layer (13); and removing a portion of the first oxide layer (13) from the substrate (10) surface and removing the first and second oxide a seed for growing a selective semiconductor layer in the trench (12).
References Cited (Backward Citations)
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