Multiple photolithographic exposures with different non-clear patterns
AssigneeMosel Vitelic, Inc.
InventorJohn Cauchi
Life of this patent
Estimating the term…
Abstract
A photoresist layer is exposed two or more times. One exposure is conducted through a regular mask, and one exposure through a modified mask with a non-clear region extending beyond a convex boundary of the non-clear region of the regular mask. The exposure through the modified mask allows one to reduce the exposure dose used with the regular mask, and thus alleviates the resist overexposure near convex areas of the non-clear pattern of the regular mask. Other embodiments are also provided.
Claims13
A method for processing a layer of material sensitive to radiation, the layer being formed on a substrate, the method comprising:
- irradiating the material with said radiation;
- and
- developing the material to remove a portion of the material and expose a portion of the substrate, creating a pattern defined by the exposed portion of the substrate;
- wherein the irradiating operation comprises:
- (a) irradiating said material through a first mask which has a clear region and a non-clear region;
- and
- (b) irradiating said material through a second mask which has a clear region and a non-clear region;
- wherein the non-clear region of the first mask covers a position of the non-clear region of the second mask, and the non-clear region of the first mask extends beyond a boundary of the position of the non-clear region of the second mask.
A mask set for processing a layer of material sensitive to radiation, the layer being formed on a substrate, the mask set comprising:
- a first mask which has a clear region and a non-clear region;
- and
- a second mask which has a clear region and a non-clear region;
- wherein the non-clear region of the first mask covers a position of the non-clear region of the second mask, and the non-clear region of the first mask extends beyond a boundary of the position of the non-clear region of the second mask.
Dependencies are inferred from the claim text.