TW201306172A - A method for making a semiconductor device - Google Patents

Abstract

The invention is about a method for making a semiconductor device. The method comprises the use of a through-silicon-via (TSV) process and a semiconductor process, and the TSV process is a via-first process. Especially, before providing the TSV process, the wafer is thinned to a predetermined thickness, and then each surface of both sides of the thinned wafer is covered with a dry film, thus, to prevent the wafer breaking during the thinning process and the TSV process.

Description

Semiconductor device manufacturing method

The present invention relates to a method of fabricating a semiconductor device, and more particularly to a method of fabricating a semiconductor device including a through silicon via (TSV) process.

The use of through-transistor via (TSV) process technology to electrically connect stacked chips in a three-dimensional integrated circuit (3D IC) is a new generation technology that has attracted much attention in recent years. There are two main processes for making the perforation of the crucible, one is the via first process and the other is the via last process. The front perforation process is to complete the perforation before the wafer fabrication step, and the post perforation process is The TSV process is performed at the packaging stage after the wafer fabrication step. Both processes have their own advantages and disadvantages, and become the two mainstreams of TSV technology because of different usage requirements.

At present, the specific process steps for forming a semiconductor device by a via process are: firstly forming a plurality of blind holes at a specific position on a wafer, filling the blind holes with conductive materials, and then performing a semiconductor process step, for example, forming a complementary gold. Oxygen semiconductor (CMOS), and post-wafer wire processing (BEOL), then polishing the backside of the wafer to thin the wafer so that the blind via becomes a through-wafer.

However, since the distance between the blind vias is very close, the wafer is easily broken during the polishing process of the wafer thinning, resulting in low process yield and increased manufacturing cost.

Accordingly, it is an object of the present invention to provide a method of fabricating a semiconductor device that can prevent wafers from being broken and improve process yield.

Therefore, the method for fabricating the semiconductor device of the present invention comprises: a through-silicon via (TSV) process step and a semiconductor process step, wherein a wafer is thinned before the through-silicon via (TSV) process step and the semiconductor process step are performed. After a predetermined thickness is formed, a dry film is respectively coated on both surfaces of the thinned wafer, and then a through-silicon via (TSV) process step is performed on the wafer, and then a semiconductor process step is performed.

The effect of the present invention is that the wafer is thinned before the TSV process is performed, that is, in the process of wafer grinding and thinning, the wafer is a complete block and has high strength to resist the application of the grinding process. The external force makes the wafer less susceptible to cracking during the thinning process, and the dry film is coated on both surfaces of the thinned wafer, which can be used as a protective layer and a support structure in the TSV process, respectively, and can not only make deep perforations. And can avoid wafer cracking after thinning, and can improve the overall process yield.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

Before the present invention is described in detail, it is noted that in the following description, similar elements are denoted by the same reference numerals.

A preferred embodiment of the method for fabricating a semiconductor device of the present invention comprises a through-silicon via (TSV) process step and a semiconductor process step, wherein the specific implementation steps of the semiconductor process can be performed by using existing semiconductor process technology, and can be adjusted according to usage requirements. It is not the focus of the present invention, and only the details of the TSV process are described in detail below.

Referring to Fig. 1, before performing the TSV process, the wafer 1 is thinned to a predetermined thickness, that is, the wafer 1 is thinned, and the thickness of the thinned wafer 1' can be adjusted according to the use requirements.

Further, a dry film 2 is coated on both surfaces of the thinned wafer 1', and the dry film 2 can be bonded to the surface of the wafer 1' by thermal compression bonding. In the present embodiment, the dry film 2 coated on the upper surface of the wafer 1' is patterned to define a position where a via is to be formed on the wafer 1', and is used as the etched wafer 1' to form a via. Protective layer. Since the thickness of the dry film 2 can be several tens of micrometers or even 100 micrometers, it is thicker than the general wet photoresist, and can be used to resist etching for a long time when making deep perforations. Protect the parts that do not require etching. Further, the dry film 2 coated on the lower surface of the wafer 1' is used to support the wafer 1'. Since the structure after the formation of the perforations of the wafer 1' is relatively fragile, especially when the perforation density is high, the dry film 2 of the lower surface can provide support to prevent the wafer 1' from being broken.

Then, a through-silicon via (TSV) process step is performed on the wafer 1' coated with the dry film 2, and the through-silicon via (TSV) process includes: patterning one of the dry films 2 (ie, the dry film on the upper surface 2) To define a position for forming a plurality of through holes 11 through the wafer 1' at the wafer 1', as shown in FIG. 1, the dry film 2 on the upper surface of the wafer 1' is patterned, and on the dry film 2 A plurality of through holes 21 are formed, and the positions of the through holes 21 are formed to be positions where the through holes 21 extend to penetrate the through holes 11 of the wafer 1'.

Next, a plurality of through holes 11 penetrating the wafer 1' are formed by the patterned dry film 2. Specifically, in the embodiment, the through-holes 11 formed in the wafer 1' can be covered by the existing wafer etching technology, and the patterned dry film 2 is used as a protective layer to cover the surface of the wafer 1'. The portion of the dry film 2 is not etched or damaged.

After the perforations 11 are formed, the dry film 2 on both surfaces of the wafer 1' is removed.

A vertical wire 3 extending through the wafer 1' is then formed in the through hole 11. The step of forming the vertical wires 3 can be carried out using existing techniques and will not be described in detail herein.

Thereafter, a semiconductor process step is performed on the wafer 1' having the vertical wires 3.

In summary, the present invention thins the wafer 1 before performing the TSV process, that is, during the polishing and thinning of the wafer 1, the wafer 1 is a complete block with high strength to resist grinding. The external force applied by the process makes the wafer 1 less susceptible to cracking during the thinning process, and the dry film 2 is respectively coated on both surfaces of the thinned wafer 1', which can be used as a protective layer and a support structure in the TSV process, respectively. Not only can the deeper perforations 11 be made, but the thinned wafer 1' can be prevented from being broken, and the overall process yield can be improved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

1. . . Wafer

1'. . . Wafer

11. . . perforation

2. . . Dry film

twenty one. . . Through hole

3. . . Vertical wire

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart showing the steps of a preferred embodiment of a method of fabricating a semiconductor device of the present invention.

1. . . Wafer

1'. . . Wafer

11. . . perforation

2. . . Dry film

twenty one. . . Through hole

3. . . Vertical wire

Claims (2)

A method for fabricating a semiconductor device, comprising: a through-silicon via (TSV) process step and a semiconductor process step, characterized in that: first thinning a wafer to a predetermined thickness; and then thinning the two wafers The surface is coated with a dry film respectively; then a through-silicon via (TSV) process step is performed on the wafer, followed by a semiconductor process step. The method of fabricating a semiconductor device according to claim 1, wherein the through-silicon via (TSV) process comprises: patterning one of the dry films to define a plurality of through-wafers formed on the wafer. a location of the perforations; forming a plurality of perforations through the wafer through the patterned dry film; removing a dry film on both surfaces of the wafer; forming vertical wires through the wafer within the perforations.