TW201911477A - Semiconductor process and semiconductor structure - Google Patents

Abstract

The invention provides a semiconductor process and a semiconductor structure. A semiconductor substrate is half cut in the front, then a protective membrane is arranged on the front of the semiconductor substrate, and then the semiconductor substrate is thinned in the back so as to separate each semiconductor unit structure, so that reduced cutting depth prevents a cutting knife from being overused, an active surface of the semiconductor substrate is protected from damage in the process of separating each semiconductor unit, and each semiconductor unit is prevented from deviating in separation. In addition, according to the semiconductor process provided in the invention, the front of the semiconductor substrate is protected by the protective membrane, then plastic packaging and cutting of a plastic packaging material are carried out, so that bad effect of plastic packaging on the front of the semiconductor substrate is prevented; and each of six surfaces of finally formed semiconductor structure has a protective layer, thereby preventing bad effect of external environment on the semiconductor structure, and improving the reliability of the semiconductor structure.

Description

Semiconductor process and semiconductor structure

The present invention relates to the field of designing semiconductor technologies, and in particular, to a semiconductor process and a semiconductor structure.

Wafer-level packaging technology is a technology in which wafers are used as processing objects to package multiple wafers on a wafer at the same time, and finally cut into a single device that can be directly mounted on a substrate or a printed circuit board. Wafer-level packaging is widely used in mobile and portable electronic products due to its high processing efficiency, low manufacturing cost, and its advantages of lightness, thinness, shortness, and smallness. FIG. 1 is a schematic diagram of a single chip package device formed by the existing wafer packaging technology, which is mainly composed of a bare wafer 01, a front protective layer 02, an electrode 03, and a back protective layer 04. The electrode 03 is formed through the opening of the front protective layer 02 and The electrode pad 011 on the front surface of the bare chip 01 is electrically connected to serve as an external pin for the chip package device shown in FIG. 1 to be electrically connected to the outside. It can be seen from FIG. 1 that the single wafer package device formed by the existing wafer-level packaging process has only a front surface and a back surface provided with a protective layer, and the other four sides are exposed, which is easily affected by external forces, thereby affecting the reliability of the wafer package device. .

In view of this, the present invention provides a semiconductor process and a semiconductor structure to protect all six sides of the semiconductor structure, thereby ensuring the reliability of the semiconductor structure. A semiconductor manufacturing process includes: 包括 cutting a predetermined depth along a cutting path on the front surface of a semiconductor substrate, 贴 pasting a protective film on the front surface of the semiconductor substrate, thinning the back surface of the semiconductor substrate, The plurality of semiconductor unit structures in the semiconductor substrate are separated. Preferably, the semiconductor manufacturing process further includes: (i) performing a plastic packaging process to form a plastic package encapsulating each of the semiconductor unit structures, and (ii) removing the protective film so that each of the first surfaces of the plastic packages is exposed. The front side of the semiconductor unit structure. Preferably, the semiconductor manufacturing process further includes: forming a patterned front surface protection layer on the first surface of the plastic package, the front surface protection layer exposing electrode pads on each of the semiconductor unit structures, and forming and The pins electrically connected to each of the electrode pads are cut along the molding compound between each of the semiconductor unit structures to separate each of the semiconductor unit structures, and the sides of each of the semiconductor unit structures are plastically sealed. Material encapsulation. Preferably, the semiconductor manufacturing process further includes: before cutting the plastic package, a thinning process is started at the second surface of the plastic package to reduce the thickness of each semiconductor unit structure, and then A back surface protective layer is formed on the back surface of the semiconductor unit structure, and the second surface of the plastic package is opposite to the first surface. Preferably, the back surface of the semiconductor substrate is polished to separate a plurality of semiconductor units on the semiconductor substrate. Preferably, the front surface of the semiconductor substrate is an active surface, and electrode pads are provided on the active surface. Preferably, after the injection molding material is injected, the adhesion between the protective film and the front surface of the semiconductor unit structure is invalidated by heating or irradiating ultraviolet rays to remove the protective film. Preferably, the plastic packaging process includes: 设置 Setting a mold on the back surface of the semiconductor structure unit, but injecting a molding compound between the protective film and the mold to form the plastic package. Preferably, the semiconductor substrate is a wafer, the semiconductor unit structure is a wafer unit on the wafer, and the semiconductor process is a wafer-level packaging process. (2) A semiconductor structure prepared according to any one of the semiconductor processes described above. It can be seen from the above that the semiconductor process provided by the present invention firstly performs a half cut from the front surface of the semiconductor substrate, then sets a protective film on the front surface, and then performs a thinning process from the rear surface of the semiconductor substrate to separate the individual semiconductor unit structures, thereby It can not only reduce the cutting depth to reduce the use of cutting tools, but also avoid the damage of the active surface of the semiconductor substrate during the separation of individual semiconductor units, and prevent the position shift of the individual semiconductor units during the separation process. . In addition, according to the semiconductor manufacturing process provided by the present invention, after the front surface of the semiconductor substrate is protected by the protective film, a plastic packaging process and a cutting process of the molding compound are performed, thereby avoiding the adverse effect of the plastic packaging process on the front surface of the semiconductor substrate, and finally forming the semiconductor The six surfaces of the structure are provided with protective layers, which can prevent the adverse influence of the external environment on the semiconductor structure and improve the reliability of the semiconductor structure.

Hereinafter, the present invention will be described in more detail with reference to the drawings. In each drawing, the same components are represented by similar drawing marks. For clarity, the various elements in the figures have not been drawn to scale. In addition, some well-known parts may not be shown. For the sake of brevity, the structure obtained after several steps can be described in one figure. In the following, many specific details of the present invention are described, such as the structure, materials, dimensions, processing processes, and techniques of each component in order to better understand the present invention. As will be understood by those skilled in the art, the invention may be practiced without these specific details. FIGS. 2a-2j are schematic cross-sectional structure diagrams of each process step of a semiconductor process according to an embodiment of the present invention. The semiconductor process provided by the present invention will be specifically described below with reference to FIGS. 2a-2j. The semiconductor process provided by the present invention mainly includes the following steps. Step 1: Cut a predetermined depth along a scribe line on the front surface of the semiconductor substrate. As shown in FIG. 2 a, the semiconductor substrate 1 includes a plurality of semiconductor unit structures 11, and the scribe lines 12 on the front surface of the semiconductor substrate 1 are located between the semiconductor unit structures 11. The front surface of the semiconductor substrate 1 is an active surface, and the electrode pad 111 is provided on the active surface. The back surface of the semiconductor substrate 1 is a surface opposite to the active surface. As shown in FIG. 2b, the cutting process is started at the position of the scribe line 12 on the front surface of the semiconductor substrate 1, and when cutting to a predetermined depth, the dicing is stopped to form an opening at the scribe line 12. Wherein, the predetermined depth is smaller than the thickness of the semiconductor substrate 1 (thickness between the front surface and the back surface of the semiconductor substrate 1). That is, after the dicing process of step 1 is completed, each semiconductor unit 11 is still not separated. Step 2: A protective film 2 is stuck on the front surface of the semiconductor substrate 1. As shown in FIG. 2c, the protective film 2 may be a thermal failure film or a UV failure film (ultraviolet failure film). The protection film 2 is affixed to the front surface of the semiconductor substrate 1 after being cut to a predetermined depth, and covers the semiconductor unit structures 11. The openings on the front surface and the dicing track 12 achieve protection of the active surface of the semiconductor substrate 1 to prevent adverse effects on the active surface of the semiconductor substrate 1 by subsequent processes. Step 3: The back surface of the semiconductor substrate 1 is thinned to separate the plurality of semiconductor unit structures 11 in the semiconductor substrate 1. As shown in FIG. 2d, after step 2 is completed, in order to facilitate subsequent processes, the semiconductor substrate 1 is first turned over so that the back surface of the semiconductor substrate 1 faces upward and the front surface faces downward, and then the back surface of the semiconductor substrate is thinned. Each semiconductor unit structure 11 is separated, and each separated unit structure 11 is adhered to the protective film 2 with the front surface facing the protective film 2 without being scattered. Therefore, in addition to protecting the active surface of the semiconductor substrate 1 from being damaged, the protective film 2 is also used to fix the position of each semiconductor unit structure 11 in step 3. Specifically, in this embodiment, a process of polishing the back surface of the semiconductor substrate 1 may be used to implement a thinning process on the back surface of the semiconductor substrate 1 to separate the semiconductor substrate into a plurality of semiconductor unit structures. It can be seen that after half-cutting the front surface of the semiconductor substrate 1, a protective film 2 is provided on the front surface thereof, and then a thinning process is performed on the rear surface of the semiconductor substrate 1 to separate the individual semiconductor unit structures 11, so that both Reducing the cutting depth to reduce the transitional use of cutting tools, and also to avoid damage to the active surface of the semiconductor substrate 1 during the process of separating individual semiconductor units 11, and to prevent the positional deviation of each semiconductor unit 11 during the separation process . In addition, the semiconductor process steps provided by the present invention further include the following steps. Step 4: As shown in FIG. 2e, a plastic packaging process is performed to form a plastic package encapsulating each semiconductor unit structure 11. Specifically, in this embodiment, the specific steps of performing the plastic packaging process may include: setting a mold on the back surface of the semiconductor structure unit 11, and then injecting a molding compound 3 between the protective film and the mold to form the plastic package. The plastic package is covered on the protective layer 2 by the back surface of each semiconductor unit structure 11, and encapsulates each semiconductor unit structure 11 together with the protective layer 2. Step 5: As shown in FIG. 2f, the protective film 2 is removed, so that the first surfaces of the plastic packages expose the front surfaces of the respective semiconductor unit structures 11. Since the protective film 2 can be a thermal failure film or a UV failure film, the adhesion between the protection film 2 and the first surface of the plastic package body can be disabled by heating or ultraviolet irradiation, so that the protection film 2 and all The first surface of the plastic package and the front surface of the semiconductor unit structure 11 are separated, so that the protective film 2 is removed, so that the electrode pad 111 on the semiconductor unit structure 11 is also exposed by the first surface of the plastic package, so as to facilitate subsequent processes. Making of pins. Step 6: As shown in FIG. 2g, a patterned front surface protection layer 4 is formed on the first surface of the plastic package, and the front surface protection layer 4 exposes the electrode pads 111 on the front surface of each semiconductor unit structure 11. The front protective layer 4 may be a hard material such as glass or silicon wafer formed by a temporary bonding process. Step 7: As shown in FIG. 2h, a pin 5 electrically connected to each electrode pad 111 is formed. The pin 5 is electrically connected to the pad electrode 111 through the opening of the front protective layer 4, and the pin 5 is exposed by the front protective layer 4 to serve as a contact for electrically connecting the semiconductor unit structure 11 with an external circuit. Specifically, in this embodiment, the pin 5 includes a first portion extending to the front protective layer 4 and electrically connected to the pad electrode 111 and a second portion located on the front protective layer 4, and in other embodiments, The pins may include a redistribution layer and a conductive ball located on the redistribution layer, wherein the redistribution layer is electrically connected to the electrode pad 111 through the opening of the front protective layer 4 and extends on the front protective layer 4. Step 8: Cut the plastic packaging body along the molding compound 3 between each semiconductor unit structure 11 to separate each semiconductor unit structure 11 so that the sides of each semiconductor unit structure 11 are encapsulated by the molding compound 3. Specifically, after the plastic package is cut, the back surface and the side surfaces (four sides perpendicular to the back surface) of each semiconductor unit structure 11 are all encapsulated by the molding compound, and the front surface of each unit structure 11 except the lead 5 is all It is covered by the front protective layer 4, so the six sides of each semiconductor unit structure 11 are protected, thereby preventing the semiconductor unit structure 11 from being adversely affected by the external environment. In this embodiment, in order to further reduce the thickness of the semiconductor unit structure 11, before performing step 8, a thinning process may be started at the second surface of the plastic package to reduce the thickness of each semiconductor unit structure. Then, a back surface protective layer 6 is formed on the back surface of the semiconductor unit structure. As shown in FIG. 2i, after forming the back surface protective layer 6, the plastic package 3 and the back surface protective layer 6 on the back surface are cut to form a pattern. 2j semiconductor structure. The second surface of the plastic package is opposite to the first surface. In this embodiment, the semiconductor substrate 1 is a wafer, and the semiconductor unit structure is a wafer unit (ie, a semiconductor bare wafer). The semiconductor process provided according to the present invention is a wafer-level packaging process in this embodiment, which is in contrast to a conventional wafer. The difference between the round-level packaging process is that the wafer-level packaging process provided by the embodiment of the semiconductor process of the present invention further includes a process of forming a protective layer for the sidewall of the wafer. As can be seen from the above, since the semiconductor process provided by the present invention first performs a half cut from the front surface of the semiconductor substrate, a protective film is provided on the front surface thereof, and then a thinning process is performed from the rear surface of the semiconductor substrate to separate the individual semiconductor unit structures. Therefore, it is possible to reduce the cutting depth to reduce the use of cutting tools, and to avoid damage to the active surface of the semiconductor substrate during the separation of individual semiconductor units, and to prevent the positional deviation of individual semiconductor units during the separation process. shift. In addition, according to the semiconductor manufacturing process provided by the present invention, after the front surface of the semiconductor substrate is protected by the protective film, a plastic packaging process and a cutting process of the molding compound are performed, thereby avoiding the adverse effect of the plastic packaging process on the front surface of the semiconductor substrate, and finally forming the semiconductor The six surfaces of the structure are provided with protective layers, which can prevent the adverse influence of the external environment on the semiconductor structure and improve the reliability of the semiconductor structure.的 The embodiments according to the present invention are as described above. These embodiments do not describe all the details in detail, nor are they limited to the specific embodiments described. Obviously, many modifications and changes can be made according to the above description. These embodiments are selected and described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and modify and use it based on the present invention. The invention is limited only by the scope of the patent application and its full scope and equivalents.

1‧‧‧ semiconductor substrate

2‧‧‧ protective film

3‧‧‧plastic sealant

4‧‧‧ Front Cover

5‧‧‧pin

6‧‧‧back protective layer

11‧‧‧Semiconductor structural unit

12‧‧‧ Cutting Road

111‧‧‧ electrode pads

01‧‧‧ bare chip

02‧‧‧ Front Cover

03‧‧‧electrode

04‧‧‧Back protective layer

011‧‧‧ electrode pad

Through the following description of the embodiments of the present invention with reference to the drawings, the above and other objects, features, and advantages of the present invention will be more clear, in the drawings: FIG. 1 is a schematic diagram of a single chip packaging device formed by the existing wafer packaging technology FIGS. 2a-2j are schematic cross-sectional structure diagrams of each process step of a semiconductor process according to an embodiment of the present invention.

Claims (10)

A semiconductor manufacturing process is characterized by: 进行 cutting a predetermined depth along a cutting path on the front surface of a semiconductor substrate, 贴 pasting a protective film on the front surface of the semiconductor substrate, thinning the back surface of the semiconductor substrate to make the semiconductor substrate Multiple semiconductor cell structures are separated. The semiconductor process according to item 1 of the patent application scope further includes: (i) performing a plastic packaging process to form a plastic package encapsulating each of the semiconductor unit structures, and (ii) removing the protective film so that the first surface of the plastic package is exposed The front side of each of the semiconductor cell structures. The semiconductor process according to item 2 of the patent application scope, further comprising: ： forming a patterned front protective layer on the first surface of the plastic package, the front protective layer exposing each electrode pad on the semiconductor unit structure, 单元 forming The pins electrically connected to each of the electrode pads are cut along the molding compound between each of the semiconductor unit structures to separate each of the semiconductor unit structures, and the sides of each of the semiconductor unit structures are encapsulated by the molding compound. According to the third aspect of the patent application, the semiconductor process further includes: before cutting the plastic package, a thinning process is started at the second surface of the plastic package to reduce the thickness of each semiconductor unit structure Then, a back surface protective layer is formed on the back surface of the semiconductor unit structure, and the second surface of the plastic package is opposite to the first surface. According to the semiconductor process of claim 1, the rear surface of the semiconductor substrate is polished to separate a plurality of semiconductor units on the semiconductor substrate. According to the semiconductor process of claim 1, the front surface of the semiconductor substrate is an active surface, and electrode pads are provided on the active surface. The semiconductor process according to item 2 of the scope of patent application, wherein after the injection molding material is injected, the adhesion between the protective film and the front surface of the semiconductor unit structure is invalidated by heating or irradiating ultraviolet rays to remove the protective film . The semiconductor manufacturing process according to item 2 of the patent application scope, wherein the plastic packaging process includes: (1) setting a mold on the back surface of the semiconductor structural unit, and then injecting a molding compound between the protective film and the mold to form the plastic package. According to the semiconductor process of claim 1, the semiconductor substrate is a wafer, the semiconductor unit structure is a wafer unit on the wafer, and the semiconductor process is a wafer-level packaging process. A semiconductor structure is prepared according to a semiconductor process of any one of claims 1 to 9 of the scope of patent application.