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

This paper presents a cross shaped pattern on a chrome mask for the fa brication 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 imag e 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 experimen tal 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. T he drawback is that exposure dose needed is 1.2 similar to 1.5 times h igher than conventional mask in our study.