Inter-electrode gap variation methods for compensating deposition non-uniformity

1. A method for depositing a material layer over a substrate, the depositing being performed in a plasma chamber having a bottom electrode and a top electrode, comprising,

providing a substrate over the bottom electrode in the plasma chamber;

setting a first gap between the bottom and top electrodes by adjusting a vertical position of the top electrode;

performing plasma deposition to deposit a first film of the material layer over the substrate while the first gap is set between the bottom and top electrodes;

setting a second gap between the bottom and top electrodes by adjusting a vertical position of the top electrode;

performing plasma deposition to deposit a second film of the material layer over the substrate while the second gap is set between the bottom and top electrodes;

wherein the material layer is defined by the first and second films, and the first gap is varied to the second gap to offset pre-characterized non-uniformities when depositing the first film followed by the second film.

2. The method of claim 1 , wherein depositing the second film using the second gap acts to offset the pre-characterized non-uniformities when pre-characterized non-uniformities associated with depositing using the second gap are opposite in direction or magnitude than pre-characterized non-uniformities associated with depositing using the first gap.

3. The method of claim 1 , wherein performing the plasma deposition of the first film using the first gap is pre-known to experience a first non-uniformity;

wherein performing the plasma deposition of the second film using the second gap is pre-known to experience a second non-uniformity;

wherein the second non-uniformity is identified to cancel out or offset at least part of the first non-uniformity.

4. The method of claim 2 , wherein pre-characterized non-uniformities for the first gap and the second gap are associated with measurement data or modeled data for the first and second gaps, and wherein the first gap and the second gap are selected based on a target profile of uniformity for said material layer.

5. The method of claim 1 , wherein the material layer is defined by an additional third film, the additional third film being deposited using a third gap between the bottom and top electrodes;

wherein the third gap is set by varying the second gap to the third gap by adjusting a vertical position of the top electrode.

6. The method of claim 1 , wherein the plasma chamber having the set first gap is the same as the plasma chamber having the set second gap.

7. The method of claim 1 , wherein the plasma chamber having the set first gap is different than the plasma chamber having the set second gap.

8. The method of claim 1 , further comprising,

moving the substrate between the plasma chamber having the first gap to the plasma chamber having the second gap during deposition of the material layer.

9. The method of claim 1 , wherein the pre-characterized non-uniformities have characteristics that are associated with near wafer edge and center wafer profile variations.

10. The method of claim 1 , wherein the pre-characterized non-uniformities have characteristics that include wing non-uniformities, or W-shaped non-uniformities, or valley-shaped non-uniformities, or dome-shaped non-uniformities, or ripple-shaped non-uniformities, or combinations of two or more thereof.