US 8,133,642 B2 · Metal optical grayscale mask and manufacturing method thereof

Abstract

A metal optical grayscale mask includes a layer of metal film which is deposited on transparent substrate, and different transparency pattern which is formed by laser writing on the surface of the metal film. The pattern is continuous, in type of array or random pattern. The grayscale is within 3.0 OD-0.05 OD. The thickness of the metal film is 5-100 nm. A manufacturing method of the metal optical grayscale mask includes that the selected transparent substrate is rinsed by the general semiconductor rinse process, the metal film is deposited on the transparent substrate then different transparency pattern is formed by laser writing on the surface of the metal film. The pattern is continuous, in type of array or the random pattern. The grayscale mask is low in price, antistatic electricity performance is good, the resolution can surpass optical diffraction limit. The manufacturing method is simple. There is a wide band application for micro-optical components and large-scale production of micro-electro-mechanical systems.

Claims12

Dependent claims

A metal gray-scale photomask, comprising:

a transparent substrate (12) and a layer of thin metal film (11) deposited on said transparent substrate, characterized in that, a continuous, arrayed or any desired gray-scale pattern is formed on said thin metal film (11) using laser direct-writing method based on a bitmap file of a pre-designed gray-scale pattern, and gray-scale value of said gray-scale pattern is ranged from 3.0 OD to 0.05 OD, wherein a thickness of said thin metal film (11) is ranged from 5 nm to 100 nm.

A method for manufacturing a metal gray-scale photomask, the method comprising steps of:

1) rinsing a substrate:
a selected transparent substrate being rinsed by conventional rinse processing of semiconductor;
2) depositing a thin metal film:
a thin metal film having a thickness ranged from 5 nm to 100 nm being deposited on the transparent substrate which is rinsed in step 1) by using thin film depositing processing, and said thin metal film being made of Sn, In or InSn alloy;
3) forming a gray-scale mask on the deposited thin metal film in step 2) by using a laser direct writing system based on the bitmap file of a pre-designed gray-scale pattern, which is carried out in such a direct writing manner that the thin metal film (11) is written point-by-point with pulse laser or is written line-by-line with continuous laser;
wherein, the laser power is set such that the corresponding relationship between the laser power and the gray level of an objective image exhibits a monotonic function so as to realize a good corresponding relationship between the laser power and the objective gray-scale image, which fulfills the requirement for preparing a 3D structure.

3 more elements

Dependencies are inferred from the claim text.

Metal optical grayscale mask and manufacturing method thereof

Life of this patent

Metal optical grayscale mask and manufacturing method thereof

Life of this patent

Abstract

Claims12