阅读说明：本技术 金的刻蚀方法 (Etching method of gold ) 是由 黄志刚 于 2019-04-16 设计创作，主要内容包括：本发明提供一种金的刻蚀方法,包括步骤：1)提供一基底；2)于所述基底上沉积金层；3)于所述金层上形成图形金属硬掩膜；4)基于所述图形金属硬掩膜对所述金层进行干法蚀刻,以形成图形金层；5)湿法蚀刻去除所述图形金层表面上的所述图形金属硬掩膜,覆盖在所述图形金属硬掩膜侧壁表面的金层干法刻蚀所产生的副产物被同时去除。本发明在金的干法蚀刻的时加入金属硬掩膜工艺,可以在去除金属硬掩膜的同时把残留的金副产物去除干净,可有效改善器件性能,提升良率。(The invention provides a gold etching method, which comprises the following steps: 1) providing a substrate; 2) depositing a gold layer on the substrate; 3) forming a patterned metal hard mask on the gold layer; 4) performing dry etching on the gold layer based on the patterned metal hard mask to form a patterned gold layer; 5) and removing the graphic metal hard mask on the surface of the graphic gold layer by wet etching, and simultaneously removing by-products generated by the gold layer on the side wall surface of the graphic metal hard mask by dry etching. According to the invention, the metal hard mask process is added during the dry etching of gold, so that the residual gold by-product can be removed completely while the metal hard mask is removed, the device performance can be effectively improved, and the yield is improved.)

1. A gold etching method is characterized by comprising the following steps:

1) providing a substrate;

2) depositing a gold layer on the substrate;

3) forming a patterned metal hard mask on the gold layer;

4) performing dry etching on the gold layer based on the patterned metal hard mask to form a patterned gold layer;

5) and removing the graphic metal hard mask on the surface of the graphic gold layer by wet etching, and simultaneously removing by-products generated by the gold layer on the side wall surface of the graphic metal hard mask by dry etching.

2. The gold etching method according to claim 1, characterized in that: step 3) forming a patterned metal hard mask on the gold layer comprises:

3-1) depositing a metal hard mask on the gold layer;

3-2) forming a photoetching material pattern layer on the metal hard mask;

3-3) dry etching the metal hard mask to form a graphic metal hard mask;

3-4) removing the photoetching material pattern layer;

3-5) wet cleaning to remove by-products generated during the dry etching of the metal hard mask.

3. The gold etching method according to claim 2, characterized in that: and depositing the metal hard mask on the gold layer by adopting a metal sputtering process.

4. The gold etching method according to claim 1, characterized in that: and 5) etching by a wet method to remove the etching solution used by the graphic metal hard mask without reacting with gold.

5. The gold etching method according to claim 1, characterized in that: the material of the metal hard mask comprises aluminum, and the etching solution used for removing the graphic metal hard mask by wet etching in the step 5) comprises aluminum wet etching solution.

6. The gold etching method according to claim 1, characterized in that: the metal hard mask is made of titanium, and the etching solution used for removing the graphic metal hard mask by wet etching in the step 5) comprises a mixed solution of ammonia water and hydrogen peroxide.

7. The gold etching method according to claim 1, characterized in that: the base comprises a silicon substrate, an oxidation layer is arranged on the silicon substrate, and the gold layer is deposited on the surface of the oxidation layer.

8. The gold etching method according to claim 1, characterized in that: and depositing the gold layer on the substrate by adopting a metal sputtering process.

9. The gold etching method according to claim 1, characterized in that: the thickness range of the gold layer is between 1 nanometer and 10000 nanometers.

10. The gold etching method according to claim 1, characterized in that: the thickness range of the metal hard mask layer is between 2 nanometers and 10000 nanometers.

Technical Field

The invention belongs to the field of semiconductor integrated circuit manufacturing, and particularly relates to a gold etching method.

Background

Gold has found very widespread use in semiconductor wafer fabrication processes, particularly in micro-electromechanical systems (MEMS) wafer fabrication. However, gold is very stable in chemical properties and cannot be etched by dry chemical reaction, and the current dry etching of gold is directly removed by ion bombardment. However, if a conventional photoresist is used as a gold etching mask, after gold etching, the remaining gold 101 has a surface with residual etching byproducts 102 bombarded during the etching process, and these etching byproducts 102 mainly comprise gold, which is very difficult to remove due to stable chemical properties in subsequent wet cleaning, so that the residual etching byproducts 102 affect the device performance, as shown in fig. 1.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a gold etching method for solving the problem that etching byproducts which are difficult to remove are easily generated in the gold etching process in the prior art.

In order to achieve the above and other related objects, the present invention provides a gold etching method, including: 1) providing a substrate; 2) depositing a gold layer on the substrate; 3) forming a patterned metal hard mask on the gold layer; 4) Performing dry etching on the gold layer based on the patterned metal hard mask to form a patterned gold layer; 5) and removing the graphic metal hard mask on the surface of the graphic gold layer by wet etching, and simultaneously removing by-products generated by the gold layer on the side wall surface of the graphic metal hard mask by dry etching.

Optionally, the step 3) of forming a patterned metal hard mask on the gold layer includes: 3-1) depositing a metal hard mask on the gold layer; 3-2) forming a photoetching material pattern layer on the metal hard mask; 3-3) dry etching the metal hard mask to form a graphic metal hard mask; 3-4) removing the photoetching material pattern layer; 3-5) wet cleaning to remove by-products generated during the dry etching of the metal hard mask.

Optionally, a metal sputtering process is used to deposit the metal hard mask on the gold layer.

Optionally, the etching solution used for removing the patterned metal hard mask by wet etching in the step 5) does not react with gold.

Optionally, the material of the metal hard mask includes aluminum, and the etching solution used in the step 5) of removing the patterned metal hard mask by wet etching includes an aluminum wet etching solution.

Optionally, the metal hard mask is made of titanium, and the etching solution used for removing the patterned metal hard mask by wet etching in step 5) comprises a mixed solution of ammonia water and hydrogen peroxide.

Optionally, the base includes a silicon substrate, the silicon substrate has an oxide layer thereon, and the gold layer is deposited on a surface of the oxide layer.

Optionally, the gold layer is deposited on the substrate using a metal sputtering process.

Optionally, the thickness of the gold layer ranges from 1 nm to 10000 nm.

Optionally, the thickness of the metal hard mask layer ranges from 2 nm to 10000 nm.

As described above, the gold etching method of the present invention has the following beneficial effects:

the invention adds the metal hard mask process during the dry etching of the gold, and can remove the residual gold by-product while removing the metal hard mask.

The dry etching process of gold can avoid the residue of gold etching by-products, effectively improve the performance of devices and improve the yield.

Drawings

Fig. 1 is a schematic diagram illustrating that a byproduct residue is easily generated in a gold etching method in the prior art.

Fig. 2 to 9 are schematic structural diagrams showing steps of the gold etching method of the present invention.

Description of the element reference numerals

201 silicon substrate

202 oxide layer

203 gold layer

204 metal hard mask

205 patterned layer of photolithographic material

206 pattern metal hard mask

207 patterned gold layer

208 by-product

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

As in the detailed description of the embodiments of the present invention, the cross-sectional views illustrating the device structures are not partially enlarged in general scale for convenience of illustration, and the schematic views are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.

For convenience in description, spatial relational terms such as "below," "beneath," "below," "under," "over," "upper," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these terms of spatial relationship are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. Further, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

In the context of this application, a structure described as having a first feature "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed in between the first and second features, such that the first and second features may not be in direct contact.

It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.