Preprocessing method and photolithography method for wafer

Abstract

The invention provides a preprocessing method and a photolithography method for a wafer. The preprocessing method comprises steps of providing a wafer to be preprocessed; placing the wafer in a sealedcavity having a preset reaction temperature and having a preset vacuum value; spraying a nitrogen-pressurized mist-like tackifier having a preset flow value onto the upper surface of the wafer in order that the tackifier reacts with the hydroxyl groups on the surface of the wafer to remove water vapor and hydrophilic bond structures, wherein the preset flow value ranges from 2L / min to 5L / min during the preprocessing of the wafer. According to the method of the invention, since the preset flow rate value ranges from 2L / min to 5L / min during the preprocessing of the wafer, the maximum value of alithographic contact angle can be achieved in the range, Thus, the problem of photoresist drift can be solved directly by the wafer preprocessing method, without adding extra steps and without affecting productivity and cycle time.

Description

Technical field [0001] The present invention relates to the field of semiconductor technology, in particular to a wafer pretreatment method and a photolithography method. Background technique [0002] As the integration of integrated circuits becomes higher and higher, the design rules of the chips are challenged toward smaller-sized processes. In the process of downsizing, the photolithography process is one of the most important process steps in the manufacture of semiconductor devices. Its main function is to copy the pattern on the mask to the wafer for the next step of etching or ion implantation. get ready. [0003] The coating quality directly affects the quality of lithography, and the coating process is also particularly important. In the photoresist coating process, most photoresists are hydrophobic, while the hydroxyl groups and residual water molecules on the surface of the wafer are hydrophilic, which results in poor adhesion between the photoresist and the wafer. E...

AI Technical Summary

Problems solved by technology

This requires that the photolithography process of the well adopts a relatively thick photoresist, adopts a 365nm photolithography process and the thickness of the photoresist is greater than 1.8 microns, and the minimum size of the well is 1.2 microns, and the aspect ratio reaches 1.5. Mass production process In the central area of ​​the wafer, photoresist drift is prone to occur, which affects the isolation between different wells and the yield of products

[0005] The current solution to this problem is to add wet process steps before photolithography, such as treating the wafer surface with a mixture of concentrated sulfuric acid and hydrogen peroxide, changing the surface state of the wafer, thereby increasing the contact between the photoresist tackifier and the wafer surface. High adhesion can reduce the probability of failure, but this requires a large number of wet process steps, each product needs to add 2-6 wet steps, which will lead to insufficient wet process capacity, and affect the cycle time of the product and surface particles Spend

Images