JPH04225574A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To facilitate an operation by simplifying manufacturing steps of a semiconductor device having a thin part such as a semiconductor pressure sensor, etc. CONSTITUTION:A light transmission UV tape 22 coated with adhesive having properties for reducing an adhesive strength when ultraviolet rays are emitted, is stuck to one side surface 2 of a wafer 1 to protect the surface 2, the wafers 1 are held back-to-back through two plates 23 by a coupling jig 8, a V-shaped band jig 10, and dipped in etchant to etch the other side surfaces 3 of the wafers 1, thereby forming a predetermined thin part such as a pressure detecting diaphragm. Thereafter, the wafer 1 stuck with the tape 22 is removed from the jig 8, the adhesive is irradiated with ultraviolet rays through the tape 22 to almost eliminate the adhesive strength and to peel it from the wafer 1. Thus, an operation for protecting the surface 2 can be simplified.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device such as a semiconductor pressure sensor equipped with a diaphragm for detecting pressure.

0002

2. Description of the Related Art FIGS. 4 to 6 show a method of manufacturing a semiconductor pressure sensor, which is a conventional semiconductor device. FIG. 4 is a cross-sectional view showing a state in which a wafer is attached to an etching jig, and FIG. 6 is a cross-sectional view showing a wafer before being attached to a jig, and FIG. 6 is a cross-sectional view showing a wafer with a diaphragm formed by etching. In these figures, 1 is a single-crystal silicon wafer, with one surface 2 side being the front side,
In FIG. 5, a resistance strain gauge (not shown) is formed on the lower surface by impurity diffusion, and a diaphragm 4, which is a thin wall portion, is formed from the other surface 3 by etching as described later.

Wafer 1 is coated with wax 6 prior to etching.
is placed on the plate 5 coated with 150 to 20
The wafer 1 is heated to 0 [° C.] and attached to the plate 5 to form the state shown in FIG. 5, thereby protecting one side 2 of the wafer 1 from being damaged during handling or the like. Two wafers 1 are attached to a plate 5 with wax 6, and the wafers 1 are placed back to back with a spacer 7 in between, as shown in FIG.
Press the circumference of the V-band jig 1 with a coupling jig 8 divided into upper and lower halves, and press the V-band jig 1 so that the O-ring 9 is evenly pressed.
0 with tightening screw 11.

In the state shown in FIG. 4, the other surface 3 is etched with an etching solution so that a diaphragm 4 of a predetermined size is formed. When the etching is completed, remove it from the jig, make it into the state shown in Fig. 6, and apply 200% wax 6.
Wafer 1 is heated to about [°C] to soften wax 6.
Remove from plate 5. Thereafter, the wafer 1 is cleaned with an organic solvent to remove wax 6 adhering to it.

[0005]

[Problems to be Solved by the Invention] In the conventional method for manufacturing semiconductor devices, as described above, one side 2 of the wafer 1 is
The side is pasted to the plate 5 with wax 6 to protect it.
Since the etching is performed while being fixed with the coupling jig 8 and the V-band jig 10, the attachment and peeling of the wax 6 to the plate 5 must be done by heating to about 200 [°C], especially when forming the diaphragm. The rest of the work was done by hand, as the diaphragm was extremely fragile and required careful work. Furthermore, the wax 6 adhering to the wafer 1 had to be removed using an organic solvent, which took a very long time. The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a method for manufacturing a semiconductor device that can simplify the working process and does not require the use of organic solvents.

[0006]

[Means for Solving the Problems] A method for manufacturing a semiconductor device according to the present invention is to adhere a light-transmitting film-like member to one side of a wafer using an adhesive whose adhesive strength decreases when irradiated with ultraviolet rays. The method includes a step of etching the other side of the wafer, and a step of irradiating the adhesive with ultraviolet light through the film-like member to peel off the film-like member.

[0007]

[Operation] In this invention, the film-like member attached to the surface of the wafer protects the surface of the wafer from being damaged during operation. Wax is not used to attach the film-like member to the wafer, so no heating is required, and the film-like member is peeled off by irradiating ultraviolet rays to reduce the adhesive strength of the adhesive. The process of adhering to and peeling off is simplified and can be mechanized if necessary. Also, there is no need to use organic solvents to remove wax.

[0008]

[Embodiment] Figures 1 to 3 show an embodiment of the present invention. Figure 1 is a cross-sectional view showing a state in which a wafer is attached to an etching jig, and Figure 2 is a sectional view showing a state in which a wafer is attached to an etching jig. FIG. 3 is a cross-sectional view showing a wafer with a diaphragm formed by etching.

In these figures, 21 is a resist coated on one surface 2 of the wafer 1, and 22 is a light transmitting resist coated on one side with adhesive (not shown) on the wafer 1 side in FIG. The UV tape 22 is a film-like member, and after the UV tape 22 is completely attached to one surface 2 of the wafer 1 by vacuum suction, it is cut along the outer circumference of the wafer 1. All of these steps are performed by automatic machines. In addition, U
The adhesive applied to the V-tape 22 has a property that its adhesive strength is greatly reduced and almost completely disappears when it is irradiated with ultraviolet rays.

Two wafers 1 to which the UV tape 22 has been pasted as described above are placed on the plate 23 with their backs facing each other, mounted on the coupling jig 8 in the same manner as the conventional example shown in FIG. Tighten using the V band jig 10 and the tightening screws 11 so that the parts 9 are tightened uniformly. UV tape 2
The variation in the thickness of wafer 2 is several micrometers, so when wafer 1 is pressed with O-ring 9, no distortion occurs in wafer 1,
The O-ring 9 is completely in close contact with the other surface 3 of the wafer 1 to prevent the etching solution from entering. Etching is performed in the state shown in FIG. 1 to form the diaphragm 4. After completing the etching, remove it from the jig and leave it in the state shown in Figure 3.
When ultraviolet rays (UV) are irradiated from the direction shown in the figure, the adhesive force of the adhesive applied to the UV tape 22 becomes almost zero, and the UV tape 22 can be easily removed from the wafer 1, which is very fragile after the diaphragm 4 has been formed. can be removed. After that, the resist 21 is removed to complete the process.

In the above embodiment, the resist 21 was provided between the wafer 1 and the UV tape 22, but the UV tape 22 was directly attached to the wafer 1 without applying the resist 21, and the surface of the wafer 1 was coated. May be protected. Further, in the above embodiment, the semiconductor device is a semiconductor pressure sensor, but the same effect can be obtained in a method of manufacturing semiconductor acceleration sensors and other semiconductor devices.

0012

[Effects of the Invention] As described above, according to the present invention, the surface of the wafer is protected by attaching a film-like member to the wafer using an adhesive whose adhesive strength decreases when irradiated with ultraviolet rays. Therefore, the work process for surface protection becomes simple and the work becomes easier.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and is a sectional view showing a state in which a wafer is attached to an etching jig.

FIG. 2 is a sectional view showing a wafer before being attached to a jig in an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing the wafer in FIG. 2 after being etched.

FIG. 4 shows a conventional method of manufacturing a semiconductor device, and is a cross-sectional view showing a state in which a wafer is attached to an etching jig.

FIG. 5 shows a conventional method for manufacturing a semiconductor device, and is a cross-sectional view showing a wafer before being attached to a jig.

FIG. 6 is a cross-sectional view showing the wafer in FIG. 5 after being etched.

[Explanation of symbols]

1 Wafer 2 One side of the wafer 3. Other side of the wafer 4 Diaphragm 8 Coupling jig 9 O-ring 10 V band jig 22 UV tape

Claims (1)

[Claims] 1. A method for manufacturing a semiconductor device in which a thin wall portion is formed on the wafer by etching from one side of the wafer, wherein the adhesive strength is reduced by irradiating the other side of the wafer with ultraviolet rays. a step of attaching a light-transmissive film-like member with an agent; a step of performing the etching with the film-like member attached; and a step of irradiating the adhesive with ultraviolet light through the film-like member. and peeling off the film-like member from the wafer.