Patent ID: 8097473

Claim:
An alignment method in which alignment of a substrate including a first layer having a first alignment mark and a second layer overlying the first layer and having both a first pattern and a second alignment mark is performed in forming a second pattern in the second layer, the method comprising: storing first alignment measurement data to be used in alignment performed in forming both the first pattern and the second alignment mark in the second layer, the first alignment measurement data obtained by measuring the first alignment mark; obtaining second alignment measurement data by measuring the second alignment mark through a resist applied over the second layer; making a first comparison of a first difference between the first alignment measurement data and the second alignment measurement data with a first threshold; in response to the first difference being larger than the first threshold, making a second comparison of a second difference between the first alignment measurement data and third alignment measurement data with a second threshold, the third alignment measurement data obtained by measuring the first alignment mark through the resist applied over the second layer; and performing alignment of the substrate in accordance with the third alignment measurement data in response to the first difference being larger than the first threshold and the second difference being smaller than the second threshold, or in accordance with the second alignment measurement data in response to the first difference being smaller than or equal to the first threshold or the second difference being larger than or equal to the second threshold.