CROSS SHAPED PATTERN ON CHROME MASK FOR 0.5 MU-M CONTACT HOLE FABRICATION

Abstract

This paper presents a cross shaped pattern on a chrome mask for the fabrication of 0.5 mu m contact hole. Based on simulation, in comparison to the conventional 0.5 mu m square mask, the contrast of aerial image of this mask gained 1.41 % at no defocus; 8.81 % at defocus 1.5 mu m. Exposure latitude gained 22.8 % under no defocus. From the experimental pattern transfer studies on positive tone photoresist using i-line 5X stepper, this mask has an useful focus range of -1.2 similar to +1.2 mu m while conventional has a range of -0.6 similar to +0.9 mu m. The drawback is that exposure dose needed is 1.2 similar to 1.5 times higher than conventional mask in our study.