Position detecting method with observation of position detecting marks

A method of detecting a position, comprising the steps of:

• disposing a wafer with an exposure surface and an exposure mask, directing the exposure surface to said exposure mask with a gap being interposed therebetween, said wafer having a position aligning wafer mark formed on the exposure surface, said wafer mark having a linear scattering source for scattering incident light, and said exposure mask having a position aligning mask mark having a linear scattering source for scattering incident light;
• focusing scattered light from said linear scattering source of said exposure wafer and said exposure mask onto a light reception surface and obtaining images with the scattered light;
• and
• detecting a relative position of said exposure wafer and said exposure mask in the longitudinal direction of said linear scattering source of said wafer mark and said mask mark by observing said images.

A method of detecting a position, comprising the steps of:

• disposing a wafer with an exposure surface and an exposure mask, directing the exposure surface to said exposure mask with a gap being interposed therebetween, said wafer having a position aligning wafer mark formed on the exposure surface, said wafer mark having a linear scattering source for scattering incident light, and said exposure mask having a position aligning mask mark having a linear scattering source for scattering incident light;
• and
• detecting a relative position of said wafer and said exposure mask in the longitudinal direction of said linear scattering source of said wafer mark and said mask mark by applying illumination light to said wafer mark and said mask mark and observing scattered light from the scattered sources of said wafer mark and said mask mark;
• wherein in said relative position detecting step, said scattered light is observed with an optical system having an observation optical axis oblique to said exposure surface, and said illumination light is applied along a direction not allowing regular reflection-light from said wafer mark and said mask mark to become incident to said optical system.

A method of detecting a position, comprising the steps of:

• disposing a wafer with an exposure surface and an exposure mask, directing the exposure surface to said exposure mask with a gap being interposed therebetween, said wafer having a position aligning wafer mark formed on the exposure surface, said wafer mark having a linear scattering source for scattering incident light, and said exposure mask having a position aligning mask mark having a linear scattering source for scattering incident light;
• and
• detecting a relative position of said wafer and said exposure mask in the longitudinal direction of said linear scattering source of said wafer mark and said mask mark by applying illumination light to said wafer mark and said mask mark and observing scattered light from the scattered sources of said wafer mark and said mask mark;
• wherein in said relative position detecting step, said scattered light is observed with an optical system having an observation optical axis oblique to said exposure surface, and said illumination light is applied along a direction not allowing regular reflection light from said wafer mark and said mask mark to become incident to said optical system;
• and
• wherein in said relative position detecting step, an angle between a line image of the optical axis of said illumination light vertically projected on said exposure surface and a line image of the optical axis of the observation light vertically projected on said exposure surface, is smaller than 90 degrees.

A method of detecting a position, comprising the steps of:

• disposing a wafer with an exposure surface and an exposure mask, directing the exposure surface to said exposure mask with a gap being interposed therebetween, said wafer having a position aligning wafer mark formed on the exposure surface, said wafer mark having a linear scattering source for scattering incident light, and said exposure mask having a position aligning mask mark having a linear scattering source for scattering incident light;
• and
• detecting a relative position of said wafer and said exposure mask in the longitudinal direction of said linear scattering source of said wafer mark and said mask mark by applying illumination light to said wafer mark and said mask mark and observing scattered light from the scattered sources of said wafer mark and said mask mark;
• wherein in said relative position detecting step, said scattered light is observed with an optical system having an observation optical axis oblique to said exposure surface, and said illumination light is applied along a direction not allowing regular reflection light from said wafer mark and said mask mark to become incident to said optical system;
• and
• wherein said relative position detecting step comprises the steps of:
• measuring a distance between the two images vertically projected to the plane of incidence containing the optical axis of said optical system, said two images including an image formed by the scattering source of said wafer mark at an in-focus position of said optical system and an image formed by the scattering source of said mask mark at an in-focus position of said optical system;
• and
• obtaining a distance between said exposure plane and said exposure mask in accordance with the distance measured by said distance measuring step.

A method of detecting a position, comprising the steps of:

• disposing a wafer with an exposure surface and an exposure mask, directing the exposure surface to said exposure mask with a gap being interposed therebetween, said wafer having a position aligning wafer mark formed on the exposure surface, said wafer mark having a linear scattering source for scattering incident light, and said exposure mask having a position aligning mask mark having a linear scattering source for scattering incident light;
• and
• detecting a relative position of said wafer and said exposure mask in the longitudinal direction of said linear scattering source of said wafer mark and said mask mark by applying illumination light to said wafer mark and said mask mark and observing scattered light from the scattered sources of said wafer mark and said mask mark;
• wherein a plurality of scattering sources of said wafer mark and a plurality of scattering sources of said mask mark are disposed respectively on first and second straight lines perpendicular to the plane of incidence of said illumination light, and said relative position detecting step includes the step of observing at the same time scattering light from the plurality of scattering sources of said wafer mark on said first straight line and scattering light from the plurality of scattering sources of said mask mark on said second straight line.