Pattern forming method

Abstract

Forward-scatter energy E,, deposited at the center of an electron beam focused on a resist film out of energy of a forward-scattered electron, is derived. A first exposure dose D,is also obtained as a minimum exposure dose at which one of lines of a testing resist film starts to leave the center thereof when the testing resist film is developed after the lines have been irradiated with the electron beam with the exposure dose thereof varied. In this case, the resist film for forming a pattern thereon is a negative resist, and has the same composition and thickness as the testing resist film. A line-to-line distance between adjacent ones of the lines gradually increases from a value equal to or smaller than twice the length of a backscattering radius &bgr;,to a value more than twice the length of a maximum radius r,of backscattered electron's reach. And a function D(s) of a second exposure dose is obtained using the line-to-line distance as a variable. The second exposure dose is a minimum exposure dose, at which one of spaces between the lines of the testing resist film starts to leave the center thereof. An intensity distribution of energy deposited in a region of the resist film, which is outside of the backscattered electron's reach, is obtained around the center of the focused electron beam by (D,/D(s))×E,, and used for proximity effect correction.