Method for analyzing masks for photolithography

A technology of mask plate and lithography, which is applied in the field of analysis of mask plates used in lithography, and can solve problems such as complex evaluation

Active Publication Date: 2011-04-06
CARL ZEISS SMT GMBH
View PDF2 Cites 13 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in some cases the evaluation of the results of the simulations is extremely complex, for example if different focus stacks of aerial images are recorded for different ...

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
  • Method for analyzing masks for photolithography
  • Method for analyzing masks for photolithography
  • Method for analyzing masks for photolithography

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0030] In a method of analyzing a reticle for lithography, a first step involves recording an aerial image of the reticle at a focus setting. In this case, the focal point is set in a plane that is actually located in the area of ​​the photoresist layer applied to the wafer. Subsequently, the images are digitized and stored in spatial image data records. This spatial image data record is then transferred to an algorithm that simulates the exposure of a lithographic wafer. Exposure and development of a photoresist layer having a predetermined thickness applied to the surface of the wafer is simulated according to predetermined parameters such as energy dose (ie, energy input per unit area). In this case, the aerial image data record defines those locations on the photoresist layer on which light falls and those locations on which light does not shine. Exposure and development are then simulated depending on the type of photoresist. In the case of a positive photoresist, this...

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 relates to a method for analyzing masks for photolithography. In this method, an aerial image of the mask for a first focus setting is generated and stored in an aerial image data record. The aerial image data record is transferred to an algorithm that simulates a photolithographic wafer exposure on the basis of this data record. In this case, the simulation is carried out for a plurality of mutually different energy doses. Then, at a predetermined height from the wafer surface, contours which separate regions with photoresist from those regions without photoresist are in each case determined. The result, that is to say the contours, are stored for each of the energy doses in each case in a contour data record with the energy dose as a parameter. Finally, the contour data records are combined to form a three-dimensional multicontour data record with the reciprocal of the energy dose as a third dimension, and, on the basis of the transitions from zero to values different than zero in the contours, a three-dimensional profile of the reciprocal of the energy dose depending on the position on the mask is generated. This profile, the so-called effective aerial image, is output or stored or automatically evaluated. The same can also occur with sections through said profile.

Description

technical field [0001] The present invention relates to a method of analyzing reticles for lithography, wherein lithographic wafer exposure is simulated. Background technique [0002] The development trend in the production of semiconductor structures, such as those used in processors in computer technology and now more often also in exchangeable storage media, is towards the production of smaller structures in the same area. Currently available computer chips consist of about 30 different layers stacked one on top of the other, and the size of the functional structures, so-called features, is about 45 nm. The photolithographic masks used to fabricate these features must be fabricated with correspondingly high precision. In this case, the wafer is exposed up to thirty times, and a different mask is required for each layer. [0003] Aerial image analysis, for example by means of the AIMS of Carl Zeiss SMS GmbH, has long been known and established for the analysis and final ...

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
IPC IPC(8): G03F7/20
CPCG03F7/705G03F7/70666G03F7/70608G03F1/68G03F1/84H01L21/0274H01L21/0337
Inventor 乌尔里克·斯特罗斯纳托马斯·谢鲁布尔
Owner CARL ZEISS SMT GMBH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products