Phase-shift mask and method of forming the same

Abstract

In an attenuated phase-shift mask (PSM) and a method of forming the same, a phase-shift layer and a light-shielding layer are sequentially stacked on a transparent substrate. The phase-shift layer and the light-shielding layer are sequentially removed from the substrate, to form a light-shielding pattern including a first opening and a phase-shift pattern including a second opening that is connected to the first opening and partially exposes the transparent substrate. Then, a transmitting portion is formed through the light-shielding pattern by partially removing the light-shielding pattern. The transmitting portion includes at least one portion of the phase-shift pattern on which a transmittance controller is formed. In one embodiment, the transmittance controller comprises a metal having a high absorption coefficient, and is formed through sputtering and diffusion processes. Accordingly, the intensity deviation between 0 th and 1 st order beams may be decreased, to thereby improve the processing margin of the exposure process.

1 . A phase-shift mask (PSM), comprising:
 a transparent substrate through which light passes;   a light-shielding pattern that is positioned on the transparent substrate and prevents the light from being incident onto the transparent substrate, the light-shielding pattern defining a transmitting portion through which the transparent substrate is partially exposed and the light is incident onto the transparent substrate;   a phase-shift pattern that is positioned on the transparent substrate exposed through the transmitting portion, the phase-shift pattern shifting the phase of the light that passes through the transmitting portion; and   a transmittance controller that is positioned at an upper portion of the phase-shift pattern in the transmitting portion and controls the transmittance of the light with respect to the phase-shift pattern in the transmitting portion.   
     
     
         2 . The PSM of  claim 1 , wherein the transmitting portion has a shape corresponding to a circuit pattern that is to be transcribed onto a semiconductor substrate for manufacturing a semiconductor device. 
     
     
         3 . The PSM of  claim 1 , wherein the phase-shift pattern comprises molybdenum (Mo) and the light-shielding pattern comprises chromium (Cr). 
     
     
         4 . The PSM of  claim 1 , wherein the transmittance controller includes a material selected from the group consisting of chromium (Cr), molybdenum (Mo) and tungsten (W), and controls the transmittance of the light passing through the phase-shift pattern, to thereby decrease an intensity deviation between 0 th  and 1 st  order beams of the light. 
     
     
         5 . The PSM of  claim 1 , wherein the light includes an argon fluoride (ArF) excimer laser and the transmittance controller includes a diffusion layer having a diffusion depth of about 100 nm to about 500 nm from a top surface of the phase-shift pattern. 
     
     
         6 . The PSM of  claim 5 , wherein the phase-shift pattern has a thickness of about 400 Å to about 600 Å from a surface of the transparent substrate.