Manufacturing method for a semiconductor device, pattern generating method and nontransitory computer readable medium storing a pattern generating program

1. A manufacturing method for a semiconductor device, comprising:

forming a stepped structure on a semiconductor substrate;

forming a processing film to cover the stepped structure;

applying a resist film to the processing film;

exposing the resist film to light such that the resist film is higher in solubility at a higher portion of the stepped structure than at a lower portion of the same;

developing the exposed resist film to form a resist film on the processing film in such a manner as to be thinner at the higher portion of the stepped structure than at the lower portion of the same; and

etching the resist film and the processing film to flatten the processing film.

2. The manufacturing method for a semiconductor device of claim 1 , wherein

the exposing the resist film to light such that the resist film is higher in solubility at the higher portion of the stepped structure than at the lower portion of the same includes exposing the resist film to light via an exposure mask with differences in effective transmission rate according to a height difference in the stepped structure.

3. The manufacturing method for a semiconductor device of claim 2 , wherein the exposure mask differs in crude density of a light-shielding pattern according to the effective transmission rate.

4. The manufacturing method for a semiconductor device of claim 3 , wherein the crude density of the light-shielding pattern is given with a pattern pitch of a resolution limit or less.

5. The manufacturing method for a semiconductor device of claim 1 , wherein a film thickness distribution of the resist film is set such that the processing film is flattened when the processing film is embedded into the lower portion of the stepped structure.

6. The manufacturing method for a semiconductor device of claim 1 , wherein

the stepped structure has word lines and inter-layer insulating films stacked alternately, and

steps are formed between the word lines such that upper-layer word lines are stepped back from lower-layer word lines.

7. The manufacturing method for a semiconductor device of claim 6 , comprising:

forming contacts on the processing film such that the upper-layer word lines are connected to the lower-layer word lines at stepped-back portions.

8. The manufacturing method for a semiconductor device of claim 7 , wherein

the semiconductor device includes a columnar body penetrating through the stacked word lines, and

the columnar body includes:

a central body capable of forming a channel;

a tunnel insulating film formed on an outer peripheral surface of the central body;

a charge trap film formed on an outer peripheral surface of the tunnel insulating film; and

a block insulating film formed on an outer peripheral surface of the charge trap film.