Photoresist removing method

Abstract

The invention discloses a photoresist removal method, which comprises the methods of partial ashing and wet cleaning, i.e. removing a hard surface layer generated on the surface of a photoresist during the ion implantation process through plasma ashing technique, and cleaning the photoresist with SOM cleaning agent. The method can completely remove the photoresist, and can effectively prevent great loss of silicon on the substrate surface and avoid the appearance of severe sag, so as to ensure the performance of CMOS devices.

Description

technical field The invention relates to the technical field of semiconductor manufacturing, in particular to a method for removing a photoresist mask after ion implantation. Background technique With the rapid development of semiconductor manufacturing technology, in order to achieve faster computing speed, larger data storage capacity and more functions of semiconductor devices, semiconductor wafers are developing towards higher component density and high integration. The characteristics of CMOS devices Dimensions have entered the deep sub-micron stage, gate lengths have become thinner and shorter than ever. In order to avoid the short channel effect, a method of lightly doping the source region and the drain region, usually called extended doping, is currently used to form the lightly doped region of the NMOS device and the lightly doped region of the PMOS device. For NMOS devices, the doped n-type impurity ions are phosphorus (P + ) or arsenic (As); for PMOS devices, t...

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Problems solved by technology

But when the feature size of the device enters the process node below 65nm, the gate oxide layer becomes thinner and thinner

If the plasma ashing energy is not properly controlled, or the SPM cleaning time is not properly controlled, it is very easy to damage the gate oxide layer, and then continue to corrode the silicon in the substrate 100, resulting in the loss of silicon, resulting in a boom on the surface of the substrate 100 as shown in Figure 4. Depression 105

If the plasma ashing process is not used, and the hard surface layer 150 and photoresist 130 are simply removed by wet cleaning, although the chance of damage to the gate oxide layer can be reduced, when the ion implantation energy is high, the hard surface layer 150 and the photoresist 130 formed When the surface layer 150 is thick, it is difficult to completely remove the photoresist and hard surface layer by simple wet cleaning (all wet strip), thereby leaving photoresist residues 133 and 134 as shown in FIG. 5 on the substrate surface

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