Method for preparing alternation type phase shift optical mask and relieving mask as well as contact hole

Abstract

This invention discloses an alternating phase-shifting mask (Alt PSM) and its corresponding unpacking mask and the utilization of packed Alt PSM and unpacking mask to make a contact hole in a way of packing and unpacking. Depth of focus can be increased due to the usage of the Alt PSM and Mask error factor can be reduced. Packing and unpacking method can also reduce hole-to-separation ratio, further to reach the aim of increasing depth of focus and reducing mask error coefficient.

Description

technical field [0001] The present invention relates to an Alternating Phase-Shifting Mask (Alternating Phase-Shifting Mask; Alt PSM) and its method of manufacturing Unpacking Mask and Contact Hole, in particular to a method using The Packing And Unpacking (PAU) method is a method of manufacturing contact holes by constructing alternating phase shift masks and corresponding unpacking masks. Background technique [0002] In the semiconductor manufacturing process, semiconductor materials such as silicon or gallium arsenide (GaAs) are mainly made into components of electronic devices, such as capacitors, resistors or switches, etc. ) and other technologies to reduce the size and weight of electronic devices. Among them, since lithography technology can not only be used to transfer the pattern of the circuit layout set on the photomask to the semiconductor substrate, but also most of the etching process and ion implantation process need to use the assistance of lithography pro...

AI Technical Summary

Problems solved by technology

In addition, the mask error factor (Mask Error Factor; MEF) represents the ratio of the increase and variation of the image size to the increase and variation of the target size on the mask. The larger the value of the mask error factor, the better the image quality. The worse the control, the poor control of the imaging quality will lead to a decrease in the reliability of the lithography process

[0005] Therefore, while integrated circuits continue to develop towards high density and small volume, lithography technology with shallow depth of focus and high mask error coefficient can no longer meet the needs of current semiconductor manufacturing processes.

Although the contact hole layout with higher density of construction holes can use the alternate phase shift mask to increase the depth of focus of the lithography process and reduce the mask error coefficient value, but for the contact hole layout with low construction density, Alternating phase-shift masks cannot effectively improve the depth of focus and mask error coefficient of the lithography process

Images