Photomask blank, photomask blank manufacturing method, photomask manufacturing method using the same, and display device manufacturing method

摘要

The invention provides a photomask blank which can realize vertical cross section shape of a mask pattern and a method for manufacturing same. The invention further provides a method for manufacturinga photomask using them, and a method for manufacturing a display device. The photomask blank comprises a transparent substrate (1), a light shielding layer (2) and an anti-reflection layer (3). The light shielding layer (2) is made of chromium compound which comprises chromium and nitrogen. The anti-reflection layer (3) is made of the chromium compound which comprises chromium, nitrogen and oxygen. The content of the chromium in the anti-reflection layer (3) is lower than the content of the chromiumin the light shielding layer (2). Multiple laminates are laminated on the anti-reflection layer(3). The content of oxygen contained in the upper layer part (32) on the surface side of the anti-reflection layer (3) is higher than the content of the oxygen contained in the lower layer part (31)of the light shielding layer side of the anti-reflection layer (3). The surface side of the upper layer part (32) has a substantially carbon-free area in which the oxygen continuously increases to thetop surface, and furthermore the highest value of a ratio (O/N) between oxygen and nitrogen is above 5.