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

Method for improving semiconductor alignment precision and its opening forming method

A semiconductor and precision technology, applied in the field of alignment accuracy, can solve problems such as inability to align, reduce component reliability, and reduce accuracy, and achieve improved alignment accuracy, high alignment accuracy, The effect of improving reliability

Inactive Publication Date: 2009-04-15
UNITED MICROELECTRONICS CORP
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, a problem that often occurs in the prior art is that when the thickness of the hard mask is too thick, most of the light sources of the alignment beam will be absorbed by the hard mask, resulting in reduced alignment accuracy. It may even happen that the alignment beamline cannot penetrate the hard mask, resulting in misalignment
On the other hand, when the thickness of the hard mask is too thin, the hard mask will lose its anti-etching effect, and other material layers below it that are not expected to be etched will be damaged, reducing the reliability of the device.

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 improving semiconductor alignment precision and its opening forming method
  • Method for improving semiconductor alignment precision and its opening forming method
  • Method for improving semiconductor alignment precision and its opening forming method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0036] Generally, in the photolithography process, when alignment marks are used for alignment, a dielectric layer will be covered on the alignment marks, and a layer of hard mask will be formed on the dielectric layer, wherein the material of the alignment marks is, for example, metal , and the material of the hard mask is, for example, titanium nitride or tantalum nitride, and in the present invention, the etching selectivity ratio of the dielectric layer to the hard mask is greater than 5. Then, the diffraction pattern generated by projecting the alignment beam on the alignment mark can be reflected to the alignment sensor or the first-order diffraction interferometer alignment system to achieve alignment. It should be noted that during the process of aligning the photomask, the thickness of the hard mask will affect the alignment accuracy.

[0037] The present invention controls the thickness that hard mask forms according to following formula:

[0038] Exp(-2×thickness×a...

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

PropertyMeasurementUnit
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
Login to View More

Abstract

A method for raising alignment accuracy of semiconductor process includes covering hard mask on dielectric layer and forming alignment mark under said dielectric layer, setting an absorption index and a thickness for hard mask and making product of absorption index and thickness be at 100-750 for deciding out better thickness range to raise alignment accuracy.

Description

technical field [0001] The invention relates to a method for aligning a semiconductor, in particular to an alignment method for improving the alignment accuracy of a semiconductor process. Background technique [0002] Photolithography is a key step in the success or failure of manufacturing semiconductor devices, so it plays a pivotal role in the semiconductor process. Taking the general manufacturing process of components as an example, depending on the complexity of a product, the photolithography and exposure steps required are about 10 to 18 times. In order for the pattern of the photomask to be transferred to the wafer correctly, in the process of semiconductor manufacturing, before each exposure of the photoresist is performed, the alignment of the wafer and the photomask must be done to avoid improper The pattern transfer of the chip leads to the scrapping of the entire wafer. [0003] In the traditional exposure process, the alignment marks corresponding to the ph...

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): G03F9/00G03F7/20H01L21/027
Inventor 林思闽
Owner UNITED MICROELECTRONICS CORP