Unlock instant, AI-driven research and patent intelligence for your innovation.

Small spot off-axis alignment system based on area lighting

A technology for aligning systems and illuminating beams, applied in the field of photolithography, can solve problems affecting signal accuracy, alignment errors, and signal deformation

Active Publication Date: 2015-03-25
SHANGHAI MICRO ELECTRONICS EQUIP (GRP) CO LTD
View PDF16 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

use Figure 4 scheme, the period of the reference grating is obviously inconsistent with the period imaged by the marker (8.0 marker branch ± 1 imaging period is 8.0 μm, 8.8 marker branch ± 1 order light imaging period is 8.8 μm, and the reference grating is 8.4 μm), which It will cause deformation of the signal, affect the accuracy of the signal, and cause alignment errors

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Small spot off-axis alignment system based on area lighting
  • Small spot off-axis alignment system based on area lighting
  • Small spot off-axis alignment system based on area lighting

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0033] Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

[0034] Figure 5Shown is a structural block diagram of the alignment system according to the present invention, the alignment system includes: a light source and illumination module 1, an imaging module 2, a reference grating 3, a signal acquisition and processing module 4, an alignment mark 5, a motion table 7, Position acquisition and motion control module 8 and alignment operation and management module 9 . Wherein, the alignment mark 5 is arranged on the silicon wafer 6, and the light source and the illumination module 1 provide an illumination beam to irradiate the alignment mark 5 to form diffracted light carrying mark information, and the diffracted light is imaged onto the surface of the reference grating 3 through the imaging module . The position acquisition and motion control module 8 collects the position information of the moving...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides a novel small spot off-axis alignment system. In the alignment system, an area lighting technical idea is employed, wherein the optical axis of an illumination beam is not in the same straight line with the optical axis of an imaging module, thereby realizing + / - 1 grade interference imaging of each labeled branch at different positions, i.e., on each corresponding reference sub-grating.

Description

technical field [0001] The invention relates to the field of photolithography, in particular to an off-axis alignment system for small light spots based on area illumination. Background technique [0002] In the manufacturing process of semiconductor IC integrated circuits, a complete chip usually needs to undergo multiple photolithography exposures before it can be completed. Except for the first photolithography, the photolithography of other levels must be accurately positioned before exposure, so as to ensure the correct relative position between the graphics of each layer. Instant overlay accuracy. Normally, the overlay accuracy is 1 / 3 to 1 / 5 of the resolution index of the lithography machine. For a 100nm lithography machine, the overlay accuracy index is required to be less than 35nm. Overlay accuracy is one of the main technical indicators of a projection lithography machine, and the alignment accuracy between the mask and the silicon wafer is a key factor affecting...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): G03F7/20G03F9/00
Inventor 李运锋宋海军
Owner SHANGHAI MICRO ELECTRONICS EQUIP (GRP) CO LTD