Method of forming trench isolation without grooving
AssigneeMosel Vitelic, Inc.
InventorsHua Ji, Dong Jun Kim, Jin-Ho Kim, Chuck Jang
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Abstract
A method and structure to form shallow trench isolation regions without trench oxide grooving is provided. In particular, a method includes a two-step oxide process in which an oxide liner lines the inside surface of a trench and the trench is filled with a bulk oxide layer, preferably using a high density plasma chemical vapor deposition (HDP-CVD) process. The oxide liner and the bulk oxide layer are formed to have similar etch rates. Thus, when etching the oxide liner and the bulk oxide layer between stack structures, a common dielectric top surface is formed that is substantially planar and without grooves.
Claims26
A method of forming an isolation trench, comprising:
- forming a plurality of stack structures over a substrate;
- etching a trench in the substrate between two of the stack structures;
- forming a thermal oxide layer over the trench;
- depositing an in-situ oxide layer over the thermal oxide layer and over the two stack
- depositing a bulk oxide layer over the in-situ oxide layer to fill the trench, wherein the etch rate of the thermal oxide layer and the in-situ oxide layer is within about 10% of the etch rate of the bulk oxide layer;
- and
- etching the thermal oxide layer, the in-situ oxide layer, and the bulk oxide layer to form a dielectric top surface between the two stack structures, wherein the dielectric top surface is substantially planar and below a top surface of the two stack structures.
A method of forming an isolation trench, comprising:
- forming a plurality of stack structures over a substrate;
- etching a trench in the substrate between two of the stack structures;
- growing a thermal oxide layer over the trench;
- filling the trench using a high density plasma chemical vapor deposition process including:
- depositing an in-situ oxide layer over the thermal oxide layer;
- and
- depositing a bulk oxide layer over the in-situ oxide layer,
- wherein the etch rate of the in-situ oxide layer is within about 10% of the etch rate of the bulk oxide layer;
- and
- etching the thermal oxide layer, the in-situ oxide layer, and the bulk oxide layer to form a dielectric top surface between the two stack structures, wherein the dielectric top surface is substantially planar and below a top surface of the two stack structures.
A method of forming an isolation trench, comprising:
- forming a plurality of stack structures over a substrate;
- etching a trench in the substrate between two of the stack structures;
- forming a thermal oxide layer over the trench;
- depositing an in-situ oxide layer over the thermal oxide layer and over the two stack structures;
- depositing a bulk oxide layer over the in-situ oxide layer to fill the trench, wherein the etch rate of the thermal oxide layer and the in-situ oxide layer is substantially similar to the etch rate of the bulk oxide layer;
- and
- etching the thermal oxide layer, the in-situ oxide layer, and the bulk oxide layer to form a dielectric top surface between the two stack structures, wherein the dielectric top surface is substantially planar and below a top surface of the two stack structures.
Dependencies are inferred from the claim text.