Phase measurement device for laser interference photolithography system, and method for using same

A phase measurement device for a laser interference photolithography system, comprising:

• a first wave plate, a first polarization splitting prism, a fourth wave plate, a retroreflector, a third wave plate, a reflector, a second wave plate, a polarizer, a second polarization splitting prism, a third polarization splitting prism, a first photoelectric detector, a second photoelectric detector, and a base,
• wherein the first polarization splitting prism, the second polarization splitting prism, and the third polarization splitting prism are fixed on the base, and an emitting surface of the first polarization splitting prism is adjacent to one incident surface of the third polarization splitting prism,
• wherein an emitting surface of the second polarization splitting prism is adjacent to another incident surface of the third polarization splitting prism,
• wherein the first photoelectric detector and the second photoelectric detector are fixed on the base in a direction of an emitting surface of the third polarization splitting prism,
• wherein the first wave plate is arranged on one incident surface of the first polarization splitting prism and a fast axis direction of the first wave plate is at an angle of 45° with respect to an edge of the first polarization splitting prism, and an edge of the first wave plate is aligned with an edge of the one incident surface of the first polarization splitting prism,
• wherein the retroreflector is arranged on another incident surface of the first polarization splitting prism with a sideline direction thereof perpendicular to a bottom side of the first polarization splitting prism,
• wherein the fourth wave plate is disposed between the first polarization splitting prism and the retroreflector and a fast axis direction of the fourth wave plate is at an angle of 45° with respect to an edge of the first polarization splitting prism,
• wherein the third wave plate is arranged on an emitting surface of the first polarization splitting prism and a fast axis direction of the third wave plate is at an angle of 45° with respect to an edge of the first polarization splitting prism, and the third wave plate and the first wave plate are coaxially disposed,
• wherein the reflector and the third wave plate are coaxially disposed on an outer surface of the third wave plate away from the first polarization splitting prism,
• wherein the second wave plate is arranged between the first polarization splitting prism and the third polarization splitting prism, and is located in an optical path after a reflection of the reflector, a transmission through the third wave plate and a reflection by the first polarization splitting prism,
• wherein an edge of the second wave plate is aligned with an edge of the emitting surface of the first polarization splitting prism,
• wherein the polarizer is arranged on the emitting surface of the third polarization splitting prism and a polarization direction of the polarizer is at an angle of 45° with respect to the third polarization splitting prism,
• wherein each of the first wave plate, the third wave plate, and the fourth wave plate is a quarter wave plate, and the second wave plate is a half wave plate,
• wherein the a reference light beam with a s-polarization state is incident on the first wave plate, and is transmitted to the one incident surface of the first polarization splitting prism:
• a light beam reflected from the first polarization splitting prism, with a s-polarization state, transmits through the fourth wave plate, reflected by the retroreflector and transmits through the fourth wave plate and is converted into a light beam with a p-polarization state, and then the light beam transmits through the first polarization splitting prism, the third polarization splitting prism and the polarizer to be a first reference light beam;
• a light beam transmitted through the first polarization splitting prism transmits through the third wave plate, reflected by the reflector and transmitted by the third wave plate and is converted into a light beam with a s-polarization state, and then the light beam is reflected by the first polarization splitting prism and transmits through the second wave plate and is converted into a light beam with a p-polarization state, and then the light beam transmits through the third polarization splitting prism and the polarizer to be a second reference light beam, and
• wherein a first measurement light beam with a s-polarization state is incident on an incident surface of the second polarization splitting prism and reflected by the second polarization splitting prism, reflected by the third polarization splitting prism and transmits through the polarizer, and the light beam interferes with the first reference light beam to be a first measurement signal which is received by the first photoelectric detector to output a first measurement signal;
• a second measurement light beam with a s-polarization state is incident on the incident surface of the second polarization splitting prism and reflected by the second polarization splitting prism, reflected by the third polarization splitting prism and transmits through the polarizer, and the light beam interferes with the second reference light beam to form a second measurement signal which is received by the second photoelectric detector to output a second measurement signal.