Optical grating phase modulator for laser interference photoetching system

Patent metadata

Field	Value
Publication number	US-9869857-B2
Application number	US-201414761605-A
Country	US
Kind code	B2
Filing date	Jan 13, 2014
Priority date	Jan 17, 2013
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

An optical grating phase modulator for a laser interference photoetching system is composed of a substrate, an optical grating, an electric motor and an optical grating positioner. The optical grating, the electric motor and the optical grating positioner are all mounted on the substrate. The optical grating is circular or rectangular, and adopt transmission or reflection type optical grating. A light beam is incident on the optical grating and generates diffraction, and when the electric motor drives the optical grating to continuously move relative to the incident light beam, diffracted light will generate a frequency shift, thereby realizing the phase modulation of the light beam. The optical grating phase modulator has the advantages of high phase modulation speed, high regulation precision and wide regulation range, thereby improving the whole performance of an interference photoetching system.

First claim

What is claimed is:

1. An optical grating phase modulator for a laser interference photoetching system, wherein: the grating phase modulator is a circular grating phase modulator, and the circular grating phase modulator includes: a circular base plate; at least three circular gratings each having a different grid density; a rotary motor, and a grating positioner; wherein, the at least three circular gratings having different grid densities are mounted on the circular base plate in a peripheral direction; the output shaft of the rotary motor is coupled to the circular base plate; and the grating positioner is mounted on the circular base plate and is used to position an incident beam to be incident on the at least three circular gratings, such that when the incident beam is incident on the at least three circular gratings, diffracted light of the same order has different frequencies so as to enable phase modulation with frequency conversion.

2. A rectangular grating phase modulator for a laser interference photoetching system, wherein: the grating phase modulator is a rectangular grating phase modulator, and the rectangular grating phase modulator includes: a rectangular base plate; at least three rectangular gratings each having a different grid density; a linear motor, and a grating positioner; wherein, the at least three rectangular gratings having different grid densities are mounted on the rectangular base plate in a longitudinal direction; a rotor or stator of the linear motor is coupled to the rectangular base plate; and the grating positioner is mounted on the rectangular base plate and is used to position an incident beam to be incident on the at least three rectangular gratings, such that when the incident beam is incident on the at least three rectangular gratings, diffracted light of the same order has different frequencies so as to enable phase modulation with frequency conversion.

3. The grating phase modulator of claim 1 , wherein the circular gratings are blazed transmission gratings or blazed reflection gratings.

4. The grating phase modulator of claim 2 , wherein the rectangular gratings are blazed transmission gratings or blazed reflection gratings.

Assignees

• Univ Tsinghua

Inventors

• Zhu Yu
• Zhang Ming
• Wang Leijie
• Cheng Rong
• Yang Kaiming
• Liu Zhao
• Hu Jinchun
• Yin Wensheng
• Mu Haihua
• Hu chuxiong
• Xu Dengfeng

Classifications

• G03F7/70316

  Details of optical elements, e.g. of Bragg reflectors, extreme ultraviolet [EUV] multilayer or bilayer mirrors or diffractive optical elements · CPC title

• G02B26/06 Primary

  for controlling the phase of light (G02B26/08 takes precedence {, measuring optical phase difference G01J9/00}) · CPC title

• G03F7/70408

  Interferometric lithography; Holographic lithography; Self-imaging lithography, e.g. utilizing the Talbot effect · CPC title

• G03F7/20

  Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00) · CPC title