Half-tone phase shift mask and patterning method using thereof
View Patent ↗A half-tone phase shift mask including at least a mask substrate, a half-tone phase shift layer and a sheltering layer. The half-tone phase shift layer is a strip-like profile that forms on the surface of the mask substrate. The sheltering layer is formed on the two ends of the half-tone phase shift layer so that a portion of the half-tone phase shift layer is exposed. The sheltering layer has a width greater than the half-tone phase shift layer.
1. A method of using a half-tone phase shift mask to form a strip pattern having two thicker ends and a narrower mid section, comprising the steps of:
providing a substrate; forming a material layer over the substrate; forming a photoresist layer on flee material layer;
patterning the photoresist layer using the half-tone phase shift mask, wherein the half-tone phase shift mask comprises: a mask substrate; two sheltering layers formed as first strips on the mask substrate with a space therebetween; a half-tone phase shift layer formed as a second strip and disposed at least in the space between the first strips, wherein the second strip is thinner than the first strips; and
patterning the material layer using the patterned photoresist layer as an etching mask to form the strip.
2. The method of claim 1 , wherein material forming the mask substrate comprises quartz glass.
3. The method of claim 1 , wherein the half-tone phase shift layer shifts the phase angle of an incoming light ray by 180°.
4. The method of claim 1 , wherein material forming the half-tone phase shift layer is selected from the group consisting of chromium oxy-nitride (CrON), chromium oxide (CrO), molybdenum silicon oxy-nitride 0VIoSOxNy), amorphous carbon and silicon nitride (SIN).
5. The method of claim 1 , wherein the half-tone phase shift layer has a light transmissivity between 4% to 10%.
6. The method of claim 1 , wherein the half-tone phase shift layer has a light transmissivity around 6%.
7. The method of claim 1 , wherein material forming the sheltering layer comprises chromium.
8. The method of claim 1 , wherein the material layer comprises a conductive layer.
9. The method of claim 1 , wherein the material layer comprises a dielectric layer.