Method for determining optimal exposure parameters of the light-sensitive layers for the photolithography and a head for the implementation of this method

摘要

The subject of the present invention is a method for determining the optimal exposure parameters in a photolithography process by analysis of topographic profiles of exposed images in a photoresist layer and a device for implementing of the method. According to the invention the optimal exposure parameters in the photolithography processes are determined as follows: in a first step a test area (OT) on a substrate coated with a photoresist is determined. Then in the test area (OT) a test pattern (WT) is exposed at least twice, each time under different exposure parameters, such as exposure energy and/or focus of the optical system. All test patterns (each exposed under different conditions) are scanned in at least 10 points along a straight line, recording the heights of photoresist layer in those points forming topography profiles. After then the profile with the smallest angle between a section in the middle part of the profile connecting the local minimum and maximum and the vertical axis is selected and the exposure parameters for this very profile are determined as optimal. The device for determining the optimal exposure parameters in a photolithography process comprises a scanning probe head integrated with a system for maskless lithography, so that the movement of the scanning probe is recorded in the coordinates of the exposure system. The method and device allow for easy recognition, which areas of the photoresist layer were appropriately exposed and which was not, without the need of conducting a photoresist developing step. Analysis of the measured topography profiles as obtained by scanning in selected regions of the test area allows determining whether the exposure parameters were appropriate.