阅读说明：本技术 一种增加蒸镀制程良率的方法 (Method for increasing yield of evaporation process ) 是由 叶顺闵 林伯璋 蔡孟霖 蘇政宏 于 2021-08-17 设计创作，主要内容包括：本发明属于半导体制造技术领域,具体涉及一种增加蒸镀制程良率的方法,S1：贴胶膜,保护和避免破坏产品表面；S2：研磨：晶圆背面减薄至所需厚度；S3：蚀刻：蚀刻晶圆背面始成粗糙表面利于蒸镀；S4:真空干燥保存：待蒸镀晶圆避免曝露在空去中；S5:蒸镀：将具导电性金属离子,溅镀于蚀刻后晶圆表面作为未来各组件间的导线用；本发明防止晶圆氧化物产生,以利提高蒸镀金属离子附着在晶圆的效率。(The invention belongs to the technical field of semiconductor manufacturing, and particularly relates to a method for increasing the yield of an evaporation process, which comprises the following steps of S1: sticking an adhesive film to protect and avoid damaging the surface of the product; s2: grinding: thinning the back of the wafer to the required thickness; s3: etching: etching the back of the wafer to form a rough surface for evaporation; s4, vacuum drying and storing: the wafer to be evaporated is prevented from being exposed in the air; s5, evaporation: sputtering conductive metal ions on the surface of the etched wafer to be used as leads among the future components; the invention prevents the wafer oxide from generating, so as to be beneficial to improving the efficiency of the evaporated metal ions attached to the wafer.)

1. A method for increasing the yield of an evaporation process is characterized by comprising the following steps:

s1: sticking an adhesive film to protect and avoid damaging the surface of the product;

s2: grinding: thinning the back of the wafer to the required thickness;

s3: etching: etching the back of the wafer to form a rough surface for evaporation;

s4, vacuum drying and storing: the wafer to be evaporated is prevented from being exposed in the air;

s5, evaporation: the conductive metal ions are sputtered on the surface of the etched wafer to be used as the conducting wire between the future components.

2. The method as claimed in claim 1, further comprising a material feeding verification step before the step of S1, wherein the product is screened for quality inspection.

3. The method of claim 2, wherein the etching of step S3 comprises the steps of: coarsening and wet etching are carried out after grinding, IPA drying is carried out subsequently, the adhesive film is torn off, quality inspection is carried out, etching is carried out before evaporation is carried out on qualified products of the quality inspection, and IPA drying is carried out again after etching is finished.

4. The method as claimed in claim 3, wherein after the etching step and before the evaporation step, the wafer is dried to be vacuum-dried and stored.

5. The method as claimed in claim 4, wherein the step of inspecting the product after the step of S5 evaporation comprises vacuum packaging the product and shipping the product.

Technical Field

The invention belongs to the technical field of semiconductor manufacturing, and particularly relates to a method for increasing the yield of an evaporation process.

Background

Nowadays, semiconductor technology advances day by day, and future integrated circuit trend is to grind and thin the wafer to achieve the following packaging process to stack and package a plurality of thinned chips, and the wafer thinning can make the chip realize the advantages of low power and low on-resistance, not only effectively prolong the product life, but also more effectively improve the efficiency in use.

The Back Side metallization (Back Side Metal) is a packaging technique developed to improve the heat dissipation problem of high power ICs. The BSM uses electron beam evaporation or metal sputtering process to plate a layer of metal and substrate (heat sink/Lead frame) on the back of the wafer for bonding, so as to achieve better heat dissipation and electrical conduction effects.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a method for increasing the yield of an evaporation process. The method can effectively improve the efficiency and the product yield of the existing vacuum evaporation process.

The technical scheme of the invention is realized as follows:

a method for increasing the yield of evaporation process includes the following steps:

s1: sticking an adhesive film to protect and avoid damaging the surface of the product;

s2: grinding: thinning the back of the wafer to the required thickness;

s3: etching: etching the back of the wafer to form a rough surface for evaporation;

s4, vacuum drying and storing: the wafer to be evaporated is prevented from being exposed in the air;

s5, evaporation: the conductive metal ions are sputtered on the surface of the etched wafer to be used as the conducting wire between the future components.

Further, before the step of S1, a feed check is further included to screen out products that meet the quality control.

Further, the etching of step S3 specifically includes the following steps: coarsening and wet etching are carried out after grinding, IPA drying is carried out subsequently, the adhesive film is torn off, quality inspection is carried out, etching is carried out before evaporation is carried out on qualified products of the quality inspection, and IPA drying is carried out again after etching is finished.

Further, after the etching step is finished and before vapor deposition, drying the residual moisture of the wafer, and storing the wafer to be vapor deposited in a vacuum drying manner.

Further, after evaporation at S5, shipment inspection is performed, and products conforming to the quality inspection are vacuum-packed and shipped.

The working principle and the effect of the scheme are as follows:

compared with the prior art, the invention has the advantages that the vacuum preservation is added, the situation that the etched wafer to be evaporated is exposed to the atmosphere due to insufficient equipment machines arranged at front and rear stations or equipment machine halt can be avoided, the generation of oxides is prevented, and the efficiency of the evaporated metal ions attached to the wafer is improved.

Drawings

FIG. 1 is a flowchart illustrating a method for increasing yield of an evaporation process according to an embodiment 1 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

Example 1

As shown in FIG. 1, a method for increasing the yield of evaporation process comprises the following steps

S1: sticking an adhesive film to protect and avoid damaging the surface of the product;

s2: grinding: thinning the back of the wafer to the required thickness;

s3: etching: etching the back of the wafer to form a rough surface for evaporation;

s4, vacuum drying and storing: the wafer to be evaporated is prevented from being exposed in the air;

s5, evaporation: the conductive metal ions are sputtered on the surface of the etched wafer to be used as the conducting wire between the future components.

Before the step of S1, the method also comprises feeding verification, and screening out products which meet the quality inspection.

The etching of the step S3 specifically includes the following steps: coarsening and wet etching are carried out after grinding, IPA drying is carried out subsequently, the adhesive film is torn off, quality inspection is carried out, etching is carried out before evaporation is carried out on qualified products of the quality inspection, and IPA drying is carried out again after etching is finished.

And after the etching step is finished and before evaporation, drying the residual moisture of the wafer, and drying and storing the wafer in vacuum after evaporation.

And S5, after evaporation, carrying out shipment inspection, carrying out vacuum packaging on products meeting the quality inspection, and carrying out shipment.

In the actual production process, no protective layer on the surface layer of the wafer after grinding and etching can cause the wafer to generate oxide (oxide layer) when being exposed to the atmosphere for a long time, and the evaporation efficiency and the product yield can be influenced during the evaporation process, so that the scheme increases a mechanism of increasing vacuum storage before the evaporation station of the wafer, prevents the wafer from being exposed to the atmosphere for too long, and is favorable for ensuring the oxidation reduction of the surface layer of the wafer when the evaporation station is used.

After etching the station, the oven will be used to dry the residual moisture of the wafer, and the oven can be added with vacuum pumping function, so that the wafer is stored in vacuum until the evaporation is needed and then taken out when being dried, thereby reducing the exposure of the wafer to the atmosphere, and thus improving the evaporation efficiency and the product yield.

Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.