Method of forming patterns and apparatus for carrying out the same

A pattern forming method for projecting patterns of a first substrate onto the surface of a second substrate via optical projection means in order to form a projection image of said patterns on the second substrate surface, said method comprising the steps of:

• furnishing a phase difference pattern on any one of a first and a second plane, said first plane being one where said patterns of said first substrate are located, said second plane being any plane equivalent to said first plane, said phase difference pattern affording a predetermined phase difference to the light passing, therethrough, and then irradiating light at said phase difference pattern via said optical projection means to project said phase difference pattern onto a detecting plane in the position equivalent to the surface of said second substrate, thus forming a projection image of said phase difference pattern on said detecting plane before said patterns are projected onto the surface of said second substrate;
• detecting by use of optical detection means the light intensity distribution of said projection image of said phase difference pattern projected onto said detecting plane, the detected light intensity distribution being represented by detection signals;
• subjecting said detection signals to signal processing so as to obtain the relative positional relationship between the focal plane of said patterns and said detecting plane by use of said optical projection means;
• and
• controlling the position of said second substrate so that the position of said detecting plane coincides with the position of said focal plane of said patterns on the basis of said relative positional relationship obtained.