Masks for fabricating semiconductor devices and methods of forming mask patterns
View Patent ↗Masks for fabricating a semiconductor device and methods of forming mask patterns are provided which are capable of enhancing the breakdown voltage of the fabricated semiconductor device by accurately correcting a line width pattern error of a semiconductor substrate due to a mask error during a process for forming a well ion implantation mask pattern. A disclosed mask used to manufacture a semiconductor device having complementary N-well and P-well includes: a master mask for the complementary N-well and P-well; and a light-blocking pattern on the master mask, wherein a region of the master mask, which is not a portion of the master mask adjacent to the light-blocking pattern, is etched by a predetermined thickness to have a phase shifting function.
1. A method of forming a photolithography mask comprising:
forming a light-blocking layer on a light-transmitting mask;
forming a first resist pattern on a portion of the light-blocking layer;
etching an exposed portion of the light-blocking layer to form (i) light-blocking pattern corresponding to one of a complementary N-well and P-well and (ii) a size adjusting region comprising an exposed surface of the light-transmitting mask;
forming a second resist pattern on the light-blocking pattern and a portion of the exposed surface of the light-transmitting mask, including a portion of the size adjusting region; and
partially etching the exposed surface of the light-transmitting mask by a phase shifting depth to form (i) a phase shifted region and (ii) a non-etched region of the size adjusting region, the non-etched region of the size adjusting region being between the light-blocking pattern and the phase shifted region;
wherein the size adjusting region increases a slope of the light intensity at an end portion of the phase shifted region relative to an otherwise identical mask that does not include the size adjusting region.
2. A method as defined in claim 1 , wherein a width of a line exposed by the light-transmitting mask in an exposing process using the second resist pattern is in a range of about 0.2 to about 0.8 μm.
3. A method as defined in claim 1 , wherein widths of lines exposed by the light-transmitting mask in an exposing process using the second resist pattern are not overlapped during respective mask aligning processes for the N-well and P-well.
4. A method as defined in claim 1 , wherein the step of etching the exposed surface of the light-transmitting mask forms a non-etched region of the exposed region of the light-transmitting mask corresponding to the size adjusting region.
5. A method as defined in claim 1 , wherein the non-etched region has a width of about 0.04 μm.
6. A method as defined in claim 1 , further comprising passing light through the light-transmitting mask to form one of the N-well and the P-well.
7. A method as defined in claim 6 , further comprising passing additional light through another light-transmitting mask to form the other of the N-well and the P-well.
8. A method as defined in claim 7 , wherein the step of forming the N-well and P-well forms an overlap region between the N-well and P-well.
9. A method as defined in claim 1 , further comprising forming another light-transmitting mask and forming another light-blocking pattern thereon corresponding to the other of the complementary N-well and P-well.
10. A method as defined in claim 1 , wherein the light-blocking layer has a wide slanted surface.
11. A method as defined in claim 5 , wherein an amplitude of light passing through the non-etched region has a positive component.
12. A method as defined in claim 5 , wherein an amplitude of light passing through the non-etched region has a steep positive component.
13. A method as defined in claim 5 , wherein the intensity of light transmitted through the light-transmitting mask is substantially lower in the non-etched region than a partially etched area of the light-transmitting mask.
14. A method as defined in claim 7 , wherein the overlap region has a constant width.