Ashing method for photoresist patterns

Abstract

The invention provides an ashing method for photoresist patterns. The ashing method comprises the following steps: providing a substrate; sequentially forming photoresist patterns on the substrate at least twice; after forming the photoresist pattern each time, with the corresponding photoresist pattern as a corresponding mask, carrying out ion doping on the substrate, and doping doped ions with different contents into the corresponding photoresist pattern; and after ion doping, ashing the corresponding photoresist pattern with corresponding ashing gas containing hydrogen, wherein the ashing gases adopted for the photoresist patterns doped with the ions with different content are different in hydrogen content. The ashing method has the beneficial effects that the effects on the substrate can be reduced; the ashing rate on the photoresist patterns is also relatively high; and in addition, the control flexibility of photoresist pattern ashing is increased and the rate of ashing the photoresist patterns and the thoroughness degrees of ashing the photoresist patternscan be adjusted.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to an ashing method of a photoresist pattern. Background technique [0002] A doping process is often required in existing semiconductor manufacturing processes. When doping, it is usually necessary to first form a photoresist pattern on the surface of the substrate to be doped to cover the region that does not need to be doped, and then dope the region exposed from the photoresist pattern. After doping, an ashing process (ashing) is generally used to ash the photoresist pattern, so as to facilitate subsequent process steps. [0003] However, the ashing process in the prior art tends to affect the substrate to a certain extent when ashing the photoresist pattern, such as causing recesses on the substrate surface, which will affect the devices in the substrate and subsequent processes. The steps and the performance of the device are affected; the existing ashing process m...

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Problems solved by technology

[0003] However, the ashing process in the prior art tends to affect the substrate to a certain extent when ashing the photoresist pattern, such as causing recesses on the substrate surface, which will affect the devices in the substrate and subsequent processes. steps and the performance of the device; the existing ashing process may also affect the region that has been doped with ions, for example, resulting in changes in the distribution of ions in the doped region, thereby changing the performance of the formed semiconductor device

[0004] The existing ashing process still has the problem that it is difficult to completely ash the photoresist pattern. Complete ashing of the photoresist pattern will cause the photoresist pattern to remain, and the remaining photoresist pattern will affect the subsequent process steps.

[0005] At the same time, the ashing gas used in the existing photolithography process still has the problem of low ashing efficiency, which will affect the wafer output (wafer per hour, WPH)

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