JPH0425149A - Irradiation method of ultraviolet ray - Google Patents

Abstract

PURPOSE:To enable a UV lamp smaller than a wafer in diameter to irradiate all the surface of the wafer with ultraviolet rays by a method wherein the wafer or ultraviolet rays are rotated as the UV lamp of an ultraviolet irradiation device is provided eccentric to the wafer. CONSTITUTION:An ultraviolet irradiator 14 is provided eccentric to a wafer 1 on which an ultraviolet curing adhesive agent film 2 is pasted, and the wafer 1 or the ultraviolet irradiator 14 is made to rotate. For instance, the length of the lamp 14 is slightly larger than the diameter of the wafer 1, a vertical center line a of rotation of a support table 3 is made to extend passing through the edge of the lamp 14, ultraviolet rays are made to irradiate the wafer 1 covering it from its center to its periphery, and the support table 3 sucking the wafer 1 is made to start rotating at the same time when ultraviolet rays are made to start radiating. By this setup, a large wafer can be uniformly irradiated with UV rays by the use of a small device, and the film 2 can be separated off without inducing cracks or chips in the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an apparatus for irradiating ultraviolet light (hereinafter referred to as UV light) onto a film attached to a wafer for manufacturing integrated circuits or the like.

[Conventional technology]

During the manufacturing process of chips for electronic circuits such as integrated circuits, circuits such as transistors and circuits are formed on the surface of a semiconductor wafer and then cut into individual elements. The process involves fixing the wafer by pasting the ring frame and the semiconductor wafer with the circuit on a film with an adhesive layer, cutting the wafer into small pieces using a cutting device, and cutting the wafer into small pieces using air tweezers or collets. There is a process of peeling it off from the film using a chuck and taking it out.

[Problem to be solved by the invention]

During the cutting and separation of the wafer in the above two operations, the wafer must be strongly adhered to the film, and after cutting, when removing each element that has become a small piece, the element can be easily removed from the film. It must be in a state where it can be peeled off.

In addition, in the process of polishing the back side of a wafer after circuits are formed, a film is attached to the circuit-forming surface of the wafer in order to protect the circuit-forming surface, immersed in a solution after the process, and then the film is peeled off. However, in this case as well, the film needs to be strongly adhered to the wafer during polishing, and if it cannot be easily peeled off after polishing, there is a problem that the wafer will crack or chip when peeled off.

In order to solve these contradictory problems, films are used that have an adhesive layer that initially has strong adhesive strength, but when irradiated with UV light, the adhesive layer forms a three-dimensional network and the adhesive strength decreases. Since this UV light irradiation lamp has a size limit (length approximately 100 mm or less), UV light is applied evenly to the entire surface of a large wafer (diameter approximately 200 mm or more).
Multiple lamps are required to irradiate light, and the amount of heat generated is large, resulting in problems such as an increase in the size of the device and a large amount of energy consumption.

An object of the present invention is to solve the above-mentioned problems and provide an ultraviolet irradiation method that can uniformly irradiate large wafers with UV light using a small device.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention has been developed by attaching a film having a pressure-sensitive adhesive layer whose adhesive strength is reduced by irradiation with ultraviolet rays to a wafer for forming electronic circuits, and performing back grinding etc. The present invention provides a method in which an ultraviolet curable adhesive film is attached to the wafer surface in the process of immersing the wafer in a solution after work and then peeling it off, and after utilizing the necessary protection function, the wafer is irradiated with ultraviolet rays.

In addition, in the processing process in which a film containing a pressure-sensitive adhesive layer whose adhesive strength decreases when irradiated with ultraviolet light is applied to a wafer for forming electronic circuits and subjected to desired processing, the film is attached. The present invention also provides a method of irradiating a desired range of a wafer with ultraviolet rays by arranging the ultraviolet ray irradiation device eccentrically with respect to the wafer and rotating the wafer or the ultraviolet irradiation device.

Furthermore, in a processing process in which a film with a pressure-sensitive adhesive layer whose adhesive strength decreases when irradiated with ultraviolet light is applied to a wafer for forming electronic circuits and subjected to desired processing, the film is attached. The ultraviolet irradiation device is arranged eccentrically with respect to the wafer, and a mask having a sector-shaped opening with the center side of the wafer shortened is provided between the wafer and the ultraviolet irradiation device, and the wafer is irradiated with ultraviolet rays through this opening. Also provided is a method of uniformly irradiating the wafer with ultraviolet light from the center to the periphery by rotating the ultraviolet irradiation device and the mask to make it stand still, or by rotating the ultraviolet irradiation device together with the mask to make the wafer stationary.

[Effect]

First, a film having a pressure-sensitive adhesive layer whose adhesive strength is reduced by curing by irradiation with ultraviolet rays is attached to a semiconductor wafer for forming an electronic circuit.

Next, the wafer is subjected to operations such as back grinding, then immersed in a solution, and then the film is peeled off.

Further, when the ultraviolet irradiation device is arranged eccentrically with respect to the wafer to which the film is attached, the wafer or the ultraviolet irradiation device is rotated to irradiate the ultraviolet rays over a desired range of the wafer.

Furthermore, if a mask is installed between the wafer and the ultraviolet irradiation device with a fan-shaped opening that is narrower toward the center of the wafer, the wafer is rotated while irradiating the wafer with ultraviolet light through the opening. Uniform ultraviolet irradiation can be performed from the center to the periphery of the wafer by keeping the mask stationary or by rotating the ultraviolet irradiation device together with the mask to make the wafer stationary.

〔Example〕

In the embodiment shown in FIG. 1, 1 is a silicon wafer for forming an electronic circuit, on which is a pressure-sensitive adhesive layer that becomes three-dimensionally reticulated by irradiation with UV light and reduces adhesive strength, that is,
An adhesive film 2 having an adhesive layer is attached.

The wafer 1 is conveyed to a support table 3'2 by some transport means, and concentrically suctioned and fixed onto this table 3 by vacuum suction or the like.

Moreover, the support stand 3 described in -1- can be rotated and moved up and down by appropriate driving means.

Reference numeral 4 denotes a case, and an opening 5 at the bottom thereof is provided with a pair of work shutters 6 that open and close from side to side.

Reference numeral 7 denotes a partition plate fixed to the middle part of the case 4, and the center thereof is a cobalt filter 10 made of a glass plate.

An area mask 11 having an opening 9 is fixed on top of the filter 10, and a shack 12 that moves forward and backward in the direction of the arrow is provided at the second part of the area mask 11.

13 is a lamp house installed on case 4, and there is a U inside.
A V lamp 14 is fixed, and an exhaust fan 15 is provided at the top.

The lamp 14 is elongated, and its length is slightly longer than the radius of the wafer 1.

Further, the vertical rotational center line a of the support base 3 slightly extends over the end of the lamp 14, so that the UV light reaches the periphery from the center of the wafer 1.

Under the condition that the wafer 1 to which the film 2 has been pasted is attracted to the support stand 3 below the case 4, the work shutter 6 is opened, the support stand 3 is raised, and the wafer 1 is placed into the case 4 through the opening 5.

Next, at the same time as the shack 12 is opened, the UV lamp 14 is turned on, and UV light is irradiated onto the film 2 on the wafer 1 through the opening 9 of the area mask 11 and the cobalt filter 10.

On the other hand, since the support base 3 starts rotating at the same time as the UV light irradiation starts as described above, the entire surface of the film 2 of the wafer 1'' is irradiated with the UV light.

When the irradiation is completed, the shank 12 is closed, the lamp 14 is turned off, the support table 3 stops rotating, and is lowered to place the wafer 1 below the case 4, and the work shutter 6 is closed.

In the above operation, the opening 9 of the area mask 11 is
If it is made into a rectangle as shown in the figure, the center of the circle of wafer 1 will be exposed to UV light.
Since it is continuously irradiated with light, the closer you get to the center, the longer the exposure time becomes.

Therefore, the amount of UV light irradiated onto the film 2 increases as the film 2 approaches the center, but in order to prevent this, the aperture 9 is formed into a fan shape that becomes narrower as it approaches the center of rotation, as shown in FIG.

In addition, as shown in FIGS. 4 and 5, a circular opening 16 is provided at the center of rotation, and this is continuous with the opening S.
6. Filter 1 such as glass that reduces UV transmittance.
7 may be incorporated to make the amount of UV light irradiated uniform over the entire area of the wafer 1.

Although the embodiment shows a case where one UV lamp 14 is used, two or more lamps 14 may be used.

In this case, the lamps 14 may be arranged at different positions in the radial direction from the center of rotation.

Further, instead of rotating the wafer, the UV lamp 14 can be rotated, and in this case, the area mask 11 is also rotated together with the lamp 14.

〔Effect of the invention〕

In this invention, by irradiating ultraviolet rays as described above,
In the process of attaching a film with a pressure-sensitive adhesive layer that reduces adhesive strength to a wafer for forming electronic circuits, immersing it in a solution after operations such as back grinding, and then peeling it off, UV-curable adhesive is applied to the wafer surface. After applying the adhesive film and utilizing the necessary protection function, by irradiating it with ultraviolet rays,
This makes it easier to peel off the adhesive film, especially
In this invention, the tJV lamp of the ultraviolet irradiation device is arranged eccentrically with respect to the center of the wafer, and by rotating the wafer or the ultraviolet irradiation, the ultraviolet rays are irradiated over a desired range of the wafer, thereby reducing the diameter of the wafer. With a shorter UV lamp, the entire surface of the wafer can be irradiated with UV light. Therefore, the amount of heat generated by the ultraviolet irradiation device becomes smaller, and IJ+
Since the air fan can also be made smaller, the entire device can be made smaller.

Furthermore, if a mask having a fan-shaped opening with a shorter center side of the wafer is provided between the wafer and the ultraviolet irradiation device, the entire surface of the wafer can be uniformly irradiated with UV light.

Therefore, it is effective when it is necessary to prevent UV light from hitting the center of the wafer too much.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing an embodiment of the present invention, FIGS. 2 to 4 are partially cutaway plan views showing each side of the same area mask, and FIG. 5 is a sectional view taken along line 411i JIV-TV. It is. 1... Silicon wafer, 2... Adhesive film, 9... Opening, 11...
... Elijah mask, 14 ... LJV lamp,
16...Aperture, 17...Filter.

Claims (3)

[Claims] (1) A film with a pressure-sensitive adhesive layer whose adhesive strength decreases when irradiated with ultraviolet rays is attached to a wafer for forming electronic circuits, dipped in a solution after back grinding, etc., and then peeled off. An ultraviolet irradiation method characterized by applying ultraviolet curable adhesive film to the wafer surface and irradiating it with ultraviolet rays after applying the necessary protective function. (2) In the process of attaching a film with a pressure-sensitive adhesive layer whose adhesive strength decreases when irradiated with ultraviolet rays to a wafer for forming electronic circuits and performing the desired processing, the film is attached. An ultraviolet irradiation method comprising: placing an ultraviolet irradiation device eccentrically with respect to a wafer, and rotating the wafer or the ultraviolet irradiation device to irradiate ultraviolet rays over a desired range of the wafer. (3) In the process of attaching a film with a pressure-sensitive adhesive layer whose adhesive strength decreases when irradiated with ultraviolet rays to a wafer for forming electronic circuits and performing the desired processing, the film is attached. The ultraviolet irradiation device is placed eccentrically with respect to the wafer, and a mask having a sector-shaped opening with the center side of the wafer shortened is provided between the wafer and the ultraviolet irradiation device. An ultraviolet irradiation method characterized by uniformly irradiating ultraviolet rays from the center to the periphery of the wafer by rotating the wafer and keeping the ultraviolet irradiation device and mask stationary, or by rotating the ultraviolet irradiation device together with the mask and keeping the wafer stationary. .