Methods for filling shallow trench isolations having high aspect ratios
AssigneeMacronix International Co., Ltd.
InventorsChin-Hsiang Lin, Lee-Jen Chen
Life of this patent
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Abstract
A method of forming an isolation trench for an integrated circuit on a semiconductor substrate includes providing a semiconductor substrate having a-pad oxide layer, a nitride layer, and a patterned photoresist layer, and removing portions of the nitride layer, pad oxide layer, and semiconductor substrate to form a trench. After the trench is formed, the patterned photoresist is removed and a first fill layer is formed inside of the trench. The first fill layer is then etched back using a wet spin etch, and a second fill layer is subsequently formed over the first fill layer.
Claims22
A method of forming at least one isolation trench for an integrated circuit on a semiconductor substrate, the method comprising:
- providing a semiconductor substrate having at least one trench disposed therein;
- forming a first ill layer within the at least one trench;
- etching back the first fill layer with a wet spin etch;
- and
- forming a second fill layer over the first fill layer.
A method of filling an isolation trench, comprising:
- (a) determining a geometrical characteristic of the isolation trench;
- and
- (b) generating a wet-spin etch recipe to be used in a deposition 1, wet spin etch, deposition 2 trench filling sequence, wherein the wet-spin etch recipe is generated based upon the determined geometrical characteristic.
A method of filling isolation trenches, comprising, not necessarily in sequence:
- (a) performing a deposition 1, wet spin etch, deposition 2 trench filling sequence to fill a first trench having a first aspect ratio;
- and
- (b) performing a deposition 1, wet spin etch, deposition 2 trench filling sequence to fill a second isolation trench having a second aspect ratio;
- wherein the first aspect ratio is greater than the second aspect ratio;
- and
- wherein a spin rate of the wet spin etch in (a) is greater than a spin rate of the wet spin etch in (b).
A method of forming at least one isolation trench on a semiconductor substrate, the method comprising:
- providing a semiconductor substrate having at least one trench disposed therein, the at least one trench having a trench sidewall and a trench base;
- forming a first fill layer inside the at least one trench;
- performing a selective etch process wherein portions of the first fill layer on the trench sidewall are removed at a greater rate than a rate at which portions of the first fill layer on the trench base are removed;
- and
- forming a second fill layer over the first fill layer.
Dependencies are inferred from the claim text.