CN101625968B

CN101625968B - Method for improving wet etching performance

Info

Publication number: CN101625968B
Application number: CN200910055897.7A
Authority: CN
Inventors: 朱骏
Original assignee: Shanghai Integrated Circuit Research and Development Center Co Ltd
Current assignee: Shanghai IC R&D Center Co Ltd
Priority date: 2009-08-04
Filing date: 2009-08-04
Publication date: 2015-02-25
Anticipated expiration: 2029-08-04
Also published as: CN101625968A

Abstract

The invention provides a method for improving wet etching performance, which comprises the following steps: carrying out HMDS hydrophobic treatment on a substrate, coating an anti-reflection coating on the substrate, coating a layer of photoresist on the anti-reflection coating, carrying out exposing, developing and etching treatment, removing the partial photoresist and the anti-reflection coating, exposing the substrate to be etched, adopting organic solution for removing the residual photoresist, and taking the residual partial anti-reflection coating as a mask for carrying out wet etching treatment on the substrate. The method removes the photoresist on the surface of the substrate, reduces the height-to-width ratio of a graph, only relies on the anti-reflection coating as a wet etching mask layer and further improves the wet etching performance.

Description

Improve the method for wet etching performance

Technical field

The present invention relates to field of IC technique, particularly a kind of method improving wet etching performance.

Background technology

Photoetching technique is with the continuous progress of integrated circuit fabrication process, constantly reducing of live width, the area of semiconductor device is just becoming more and more less, and the layout of semiconductor, from common simple function discrete device, develops into the integrated circuit integrating high-density multifunction; By initial IC (integrated circuit) subsequently to LSI (large scale integrated circuit), VLSI (very lagre scale integrated circuit (VLSIC)), until the ULSI of today (ultra large scale integrated circuit), the area of device reduces further, and function is more comprehensively powerful.Consider the complexity of technique research and development, the restriction of chronicity and high cost etc. unfavorable factor, on the basis of prior art level, how to improve the integration density of device further, reduce the area of chip, as much as possiblely on same piece of substrate obtain effective chip-count, thus raising overall interests, more and more will be subject to chip designer, the attention of manufacturer.

In various semiconductor technology, wet etching technique can not produce plasma damage due to it and possess high etching selection ratio and play the part of important role in the key technologies such as grid oxygen etching, surface clean.But, this technology has a significant problem: namely etch isotropism, this means the carrying out along with longitudinally etching, its side direction etching also occurs simultaneously, side direction etching can cause device surface size to become large, this is intolerable in small-size chips, therefore, the problem how preventing from the lateral corrasion of wet etching from just becoming industry must solving, method is in the past that the thickness reducing photoresist is convenient to wet etching, fast acid is used to shorten the wet treatment time, HMDS is adopted to improve bottom adhesion etc., but these methods are owing to cannot guarantee that photoresist does not flow on substrate, thus DeGrain.

Summary of the invention

The problem that the present invention solves avoids occurring in wet etching side direction etching photoresist is flow on substrate thus causes etching not exclusively.

The invention provides a kind of method improving wet etching performance, comprise the following steps: HMDS hydrophobic treatment is carried out to substrate; Be coated with antireflecting coating over the substrate; Described antireflecting coating is coated with one deck photoresist; Carry out exposing, developing and etching processing, remove the described photoresist of part and antireflecting coating, make outside substrate to be etched is exposed to; Organic solution is adopted to remove all photoresists; With remaining partial anti-reflective coating for sheltering, wet etching treatment is carried out to substrate.

Optionally, described HMDS hydrophobic treatment comprises to substrate surface sprinkling HMDS and baking.

Optionally, the HMDS spraying time scope in described HMDS hydrophobic treatment is 0.1 second to 100 seconds.

Optionally, the baking temperature scope in described HMDS hydrophobic treatment is 30 degree to 150 degree.

Optionally, the baking time scope in described HMDS hydrophobic treatment is 1 second to 1000 seconds.

Compared with prior art, the present invention has the following advantages: do HMDS hydrophobic treatment and coating antireflecting coating to substrate, enhance the adhesion with substrate bottom photoresist; Get rid of photoresist, reduce the depth-width ratio of figure, only rely on antireflecting coating as wet etching masking layer, avoid photoresist and flow to obstruction etching on substrate, improve the performance of wet etching.

Accompanying drawing explanation

Fig. 1 is the flow chart that the present invention improves the method for wet etching performance.

Fig. 2 to Fig. 5 is the embodiment operation chart that the present invention improves the method for wet etching performance.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in detail.

The invention provides a kind of method improving wet etching performance, first, please refer to Fig. 1, Fig. 1 is the flow chart that the present invention improves the method for wet etching performance, comprise the following steps: step 21: HMDS hydrophobic treatment is carried out to substrate, the Full Name in English of HMDS is Hexamethyldisilazane, chemical name is in hexamethyl two silicon n-formyl sarcolysine alkane, after it is coated onto substrate surface, the compound generated based on siloxanes can be reacted by heating, this is actually a kind of surfactant, it successfully by substrate surface from hydrophilic become hydrophobic, its hydrophobic group can be combined with photoresist well, play the effect of coupling, moreover, in follow-up developing process, owing to it enhancing the adhesion of photoresist by antireflecting coating and substrate, thus the side direction effectively suppressing etching liquid to enter mask and substrate etches, directly be coated onto on wafer with the HMDS of liquid state, then the High Rotation Speed by wafer forms one deck HMDS film in wafer surface, so interim solve between substrate and photoresist in conjunction with problem, HMDS spraying time scope in described HMDS hydrophobic treatment is 0.1 second to 100 seconds, baking temperature scope in described HMDS hydrophobic treatment is 30 degree to 150 degree, baking time scope in described HMDS hydrophobic treatment is 1 second to 1000 seconds, preferred mode is adopted: HMDS spraying time 20 seconds in the present embodiment, baking temperature 125 degree, baking time 30 seconds, step 22: be coated with antireflecting coating over the substrate, described antireflecting coating can be used for the uniformity improving the photoetching agent pattern formed in photolithographic patterning process and the adhesion strengthened with substrate bottom photoresist, step 23: be coated with one deck photoresist in described antireflecting coating, step 24: carry out exposing, developing and etching processing, part described photoresist is removed in exposure and development, and etching removes antireflecting coating, makes outside substrate to be etched is exposed to, step 25: adopt organic solution to remove remaining photoresist, get rid of photoresist, reduce the depth-width ratio of figure, make the device made under the constant prerequisite of property retention, volume is less, in addition, only relies on antireflecting coating as wet etching masking layer, avoid photoresist and flow to obstruction etching on substrate, improve the performance of wet etching, step 26: with remaining partial anti-reflective coating for sheltering, wet etching treatment is carried out to substrate.

Then, please refer to Fig. 2 to Fig. 4, Fig. 2 to Fig. 4 is the embodiment operation chart that the present invention improves the method for wet etching performance, in Fig. 2, after HMDS hydrophobic treatment is carried out to substrate, substrate 13 is coated with antireflecting coating 12, then in antireflecting coating 12, is coated with one deck photoresist 11; In Fig. 3, carry out exposing, developing and etching processing, part described photoresist is removed in exposure and development, and etching removes antireflecting coating, makes outside substrate to be etched is exposed to; In Fig. 4, adopt organic solution to remove remaining photoresist, get rid of photoresist, reduce the depth-width ratio of figure, make the device made under the constant prerequisite of property retention, volume is less; In Fig. 5, rely on antireflecting coating 12 to carry out wet etching treatment as wet etching masking layer, avoid photoresist and flow to obstruction etching on substrate, improve the performance of wet etching.Concrete parameter can with reference to described in the preceding paragraph.

Disclose as above with preferred embodiment although the present invention is own, the present invention is not defined in this.Any those skilled in the art, without departing from the spirit and scope of the present invention, all can make various changes or modifications, and therefore protection scope of the present invention should be as the criterion with claim limited range.

Claims

1. improve a method for wet etching performance, it is characterized in that comprising the following steps:

HMDS hydrophobic treatment is carried out to substrate, strengthens the adhesion of photoresist by antireflecting coating and substrate, thus suppress the side direction of etching liquid to etch;

Be coated with described antireflecting coating over the substrate, described antireflecting coating for improvement of the photoetching agent pattern formed in photolithographic patterning process uniformity and strengthen bottom photoresist and the adhesion of substrate;

Described antireflecting coating is coated with one deck photoresist;

Carry out exposing, developing and etching processing, remove the described photoresist of part and antireflecting coating, make outside substrate to be etched is exposed to;

Organic solution is adopted to remove remaining photoresist;

With remaining partial anti-reflective coating for sheltering, wet etching treatment is carried out to substrate.

2. the method for raising wet etching performance according to claim 1, is characterized in that described HMDS hydrophobic treatment comprises and sprays HMDS and baking to substrate surface.

3. the method for raising wet etching performance according to claim 2, is characterized in that the HMDS spraying time scope in described HMDS hydrophobic treatment is 0.1 second to 100 seconds.

4. the method for raising wet etching performance according to claim 2, is characterized in that the baking temperature scope in described HMDS hydrophobic treatment is 30 degree to 150 degree.

5. the method for raising wet etching performance according to claim 2, is characterized in that the baking time scope in described HMDS hydrophobic treatment is 1 second to 1000 seconds.