Method for forming a resist protect layer on substrate and substrate having blocking protecting layer

Abstract

The invention provides a base plate with an isolation protective layer and a method for forming the isolation protective layer on the base plate. The method comprises the following steps: forming an isolation structure on the semiconductor base plate, depositing a native nitriding layer on the semiconductor layer, and the nitriding layer having an essential etching selection ratio relative to the isolation structure; later forming a photoresist mask to partly cover the native nitriding layer; carrying out wet etching of the native nitriding layer which has not yet been covered by the photoresist mask with a method which has not material damages on the isolation structure to enable the isolation protective layer to be formed on the native nitriding layer covered by the mask. The base plate with the isolation protective layer and the method effectively solve the problems that: in the prior art, an oxidation layer is used as the isolation protective layer, thereby bringing about pit defects caused by the undercut of an isolation inner covering and a damaged shallow groove isolation due to a low etching selectivity. The base plate with the isolation protective layer and the method also solve the problems that: in the prior art, a composite layer of the oxidation layer and the nitriding layer is used as the isolation protective layer, thereby being incapable of removing the nitriding layer completely, and bringing about a complicated manufacture process, a low yield, etc.

Description

technical field [0001] The present invention relates to the manufacture of a semiconductor device, in particular to a method for forming a blocking protective layer with better etching selectivity. Background technique [0002] In semiconductor devices, a metal silicide layer is usually formed on top of silicon structures, such as polysilicon gates, source / drain regions, and local interconnects, to reduce sheet resistance. In the process of forming the metal silicide layer, a barrier protective layer is used to cover part of the silicon structure and expose other predetermined regions. Depositing a metal layer on the barrier protection layer and other exposed areas is comprehensively deposited. A heat treatment step is performed to promote the chemical reaction between the metal layer and the silicon structure in contact with it to form a metal silicide layer. Since the protective layer shields the semiconductor device in the part from being in contact with the metal layer...

AI Technical Summary

Problems solved by technology

[0008] Although this process utilizes a thinner oxide layer 202 to reduce the time of the wet etch process, it still has certain disadvantages

Due to the geometry of the semiconductor structure 20, dry etching cannot completely remove the uncovered nitride layer 203, which would result in the silicon nitride layer 209 remaining at the bottom corners of the spacers 210.

In addition, because dry etching usually uses chemical gases and high-energy ions, it is very difficult to protect the semiconductor substrate from damage by chemical gases and high-energy ions when the thickness of the oxide layer 202 provided is insufficient.

In addition, this process not only requires two-step deposition to form the nitride layer 203 and the oxide layer 202, but also requires a dry etching step and a wet etching step to remove part of the above two layers, thus making the entire semiconductor device manufacturing process complicated and resulting in low yield. with high cost

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