Photomask and method of manufacturing semiconductor device using the photomask
AssigneeKabushiki Kaisha Toshiba
InventorsTakashi Sato, Kazuya Fukuhara
Life of this patent
Estimating the term…
Abstract
A photomask includes a mask substrate to be irradiated with irradiation light, and first and second phase shifters arranged on the mask substrate. The first phase shifter is arranged on the mask substrate with a first pitch not larger than eight times the wavelength of the irradiation light, has a transmittance of not more than 5% for the irradiation light, and phase-shifts the irradiation light by 180°. The second phase shifter is arranged on the mask substrate with a second pitch larger than eight times the wavelength, has a transmittance of not more than 5%, and phase-shifts the irradiation light by 180°.
Claims17
A photomask comprising:
- a mask substrate to be irradiated with irradiation light;
- a first phase shifter comprising three or more first type phase shift elements, wherein the three or more first type phase shift elements are arranged on the mask substrate with a first pitch not larger than eight times a wavelength of the irradiation light, and wherein the first phase shifter has a transmittance of not more than 5% for the irradiation light and phase-shifts the irradiation light by 180°;
- and
- a second phase shifter comprising three or more second type phase shift elements, wherein the three or more second type phase shift elements are arranged on the mask substrate with a second pitch larger than eight times the wavelength of the irradiation light, and wherein the second phase shifter has a transmittance of not more than 5%, and phase-shifts the irradiation light by 180°.
A method of manufacturing a semiconductor device comprising:
- forming a resist film on a wafer by coating;
- irradiating a photomask with irradiation light to transfer an image of a mask pattern including a first phase shifter and a second phase shifter onto the resist film, the first phase shifter comprising three or more first type phase shift elements which are arranged on the mask substrate with a first pitch not larger than eight times a wavelength of the irradiation light, having a transmittance of not more than 5% for the irradiation light, and serving to phase-shift the irradiation light by 180°, and the second phase shifter comprising three or more second type phase shift elements which are arranged on the mask substrate with a second pitch larger than eight times the wavelength of the irradiation light, having a transmittance of not more than 5%, and serving to phase-shift the irradiation light by 180°;
- and
- developing the resist film.
Dependencies are inferred from the claim text.