提出一种步进扫描投影光刻机承片台不平度检测新技术。在晶圆与承片台存在不同偏移量时,利用线性差分传感器在线测量晶圆上不同点的局部高度;通过建立临时边界条件,以递推法消除晶圆面形影响,并逐行计算出承片台的相对不平度;通过逐行计算的结果递推相邻行之间的高度差,并将该高度差叠加到每一行,以消除临时边界条件的限制,得到处于同一高度上的承片台不平度;将计算的结果作为初始值,根据最小二乘原理,以邻近的四个测量点作为参考,逐步逼近得到承片台的真实不平度。计算机仿真结果验证了该检测方法的正确性,计算结果逐步收敛并逼近真实值.实验结果表明,该方法的计算结果较好地表示了承片台的真实不平度,重复精度优于0.3 nm;同时该方法也可用于晶圆表面面形的测量。 This paper presents a new technology for detecting the irregularity of the stage of stepper scanning projection lithography machine. When there are different offsets between the wafer and the wafer stage, a linear differential sensor is used to measure the local height of the wafer at different points on the wafer. By establishing the temporary boundary conditions, the recursion method is used to eliminate the influence of the wafer surface shape, The relative unevenness out of the stage; recursive the height difference between adjacent lines by the result of the line-by-line calculation, and add the height difference to each line to eliminate the restriction of the temporary boundary conditions to obtain the same height According to the principle of least squares, taking the neighboring four measuring points as a reference, the real unevenness of the stage is obtained by stepwise approximation. Computer simulation results verify the correctness of the detection method, the calculation results converge gradually and approximate the real value.The experimental results show that the calculation results of the method better represent the real unevenness of the stage, the repeatability is better than 0.3 nm; meanwhile, The method can also be used for the measurement of the wafer surface profile.