JP3169952B2 - Ultraviolet irradiation method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial applications]

The present invention relates to a method and an apparatus for irradiating a film adhered to a wafer for manufacturing an integrated circuit or the like with ultraviolet rays (hereinafter referred to as UV light).

[0002]

[Prior art]

During the manufacturing process of electronic circuit chips such as integrated circuits, circuits such as transistors and diodes are formed on the surface of a semiconductor wafer, and then cut into individual elements. The work of attaching the ring frame and the semiconductor wafer constituting the circuit to a film having an adhesive layer to fix the wafer, and cutting the wafer with a cutting device into small-piece elements, and using a piece of air tweezers or a collet chuck for the elements. There is a work to peel off from the film and take it out.

[0003]

[Problems to be solved by the invention]

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

In a process of polishing a back surface after forming a circuit on a wafer, a film is adhered to a circuit forming surface of the wafer for the purpose of protecting the circuit forming surface, immersed in a solution after work, and then immersed in a solution. In some cases, the film must be strongly adhered to the wafer during polishing. If the film cannot be easily peeled off after polishing, there is a problem that the wafer may be cracked or chipped at the time of peeling.

In order to solve such a contradictory problem, a film having an adhesive layer having such a property that the adhesive strength is strong at first and the adhesive strength is reduced by irradiating with UV light to form a three-dimensional network. However, since the size of the UV light irradiation lamp is limited (less than about 100 mm in length), multiple lamps are required to uniformly irradiate the entire surface of a large wafer (about 200 mm or more in diameter). Lamps are required, and the amount of heat generated is large, so that there is a problem that the apparatus becomes large and energy consumption increases.

An object of the present invention is to solve the above problems and to provide an ultraviolet irradiation method and apparatus capable of uniformly irradiating a large wafer with UV light using a small apparatus.

[0007]

[Means for Solving the Problems]

The present invention provides, as a means for solving the above-mentioned problems, a processing step in which a film having a pressure-sensitive adhesive layer having a property such that the adhesive strength is reduced by ultraviolet irradiation is attached to a wafer for forming an electronic circuit and a desired processing is performed. In the above, the ultraviolet irradiation means is eccentrically arranged with respect to the wafer to which the film is adhered, the wafer or the ultraviolet irradiation means is turned, and the irradiation of the ultraviolet light is restricted according to the position in the wafer, so that the ultraviolet irradiation means is within a desired range of the wafer. This is a method of irradiating ultraviolet rays uniformly over the entire area.

Further, in a processing step of attaching a film having a pressure-sensitive adhesive layer having a property of decreasing adhesive strength by ultraviolet irradiation to a wafer for forming an electronic circuit and performing a desired processing, the wafer to which the film is attached The UV irradiating means is eccentrically arranged, and a mask having a fan-shaped opening with a narrower center side of the wafer is provided between the wafer and the UV irradiating means, and the wafer is rotated while irradiating the wafer with UV light through this opening Then, the ultraviolet irradiation means and the mask may be stopped, or the ultraviolet irradiation means may be swiveled together with the mask to stop the wafer so that uniform ultraviolet irradiation is performed from the center of the wafer to the periphery.

Further, as an apparatus for carrying out the method of the first invention, a film having a pressure-sensitive adhesive layer whose adhesive strength is reduced by irradiation with ultraviolet light is attached to a wafer for forming an electronic circuit, and a desired film is formed. In the processing step of performing the processing, the ultraviolet irradiation means is eccentrically arranged with respect to the wafer to which the film is attached, the wafer or the ultraviolet irradiation means is turned, and the irradiation of the ultraviolet light is restricted according to the position in the wafer, An ultraviolet irradiation device that uniformly irradiates ultraviolet rays over a desired range can be employed.

[0010]

[Action]

First, a film having a pressure-sensitive adhesive layer that is cured by irradiation with ultraviolet light and has a property of reducing adhesive strength is attached to a semiconductor wafer for forming an electronic circuit. The ultraviolet irradiation means is eccentrically arranged with respect to the wafer to which the film is attached,
By rotating the wafer or the ultraviolet irradiation means, ultraviolet light is irradiated over a desired range of the wafer.

Further, in the case where a mask having a fan-shaped opening in which the center side of the wafer is narrowed is provided between the wafer and the ultraviolet irradiation means, the wafer is rotated while irradiating the wafer with ultraviolet light through this opening, and the ultraviolet irradiation means is provided. Then, the mask is stopped, or the ultraviolet irradiation means is rotated together with the mask to stop the wafer, so that uniform ultraviolet irradiation can be performed from the center to the periphery of the wafer.

In the above-described ultraviolet irradiation apparatus, ultraviolet light is emitted from the ultraviolet irradiation means eccentrically arranged on the wafer while rotating either the wafer or the ultraviolet irradiation means. At this time, the irradiation amount of the ultraviolet rays is limited by the limiting means so that the irradiation amount of the ultraviolet rays is uniform at each position of the wafer.

[0013]

【Example】

In the embodiment shown in FIG. 1, reference numeral 1 denotes a silicon wafer for forming an electronic circuit, and a pressure-sensitive adhesive layer on which a three-dimensional network is formed by irradiation with UV light to reduce the adhesive force, that is, an adhesive film having an adhesive layer. 2 is affixed. The wafer 1 is sent onto the support table 3 by an appropriate transfer means, and is concentrically sucked and fixed on the table 3 by vacuum suction or the like.

The support table 3 can be turned and moved up and down by appropriate driving means. Reference numeral 4 denotes a case, and a pair of work shutters 6 which open and close left and right are provided in an opening 5 at the bottom. 7
Is a partition plate fixed to an intermediate portion in the case 4, and the center is a cobalt filter 10 made of a glass plate.

An area mask having an opening 9 on the filter 10
11 is fixed, and a shutter 12 that moves forward and backward in the direction of the arrow is further provided thereon. Reference numeral 13 denotes a lamp house provided on the case 4, in which a UV lamp 14 as an ultraviolet irradiation means is fixed, and an exhaust fan 15 is provided on the upper part.

The lamp 14 is elongated, and its length is slightly longer than the radius of the wafer 1. Further, the vertical rotation center line a of the support 3 is slightly applied to the end of the lamp 14 so that the UV light reaches the periphery from the center of the wafer 1.

The work shutter 6 is opened under the condition that the wafer 1 on which the film 2 is attached is adsorbed to the support table 3 below the case 4, and the support table 3 rises to move the wafer 1 from the opening 5 to the case 4.
Put in. Next, when the shutter 12 opens, the UV lamp
14 is turned on, and the UV light is irradiated on 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 3 starts rotating at the same time as the irradiation of the UV light starts as described above, the UV light is applied to the entire surface of the film 2 on the wafer 1. When the irradiation is completed, the shutter 12 is closed, the lamp 14 is turned off, the rotation of the support 3 is stopped, and the wafer 1 is moved downward so that the wafer 1 is below the case 4.
Closes.

In the above operation, the opening 9 of the area mask 11 is
In the case of the rectangular shape as described above, the central portion of the circle of the wafer 1 is continuously irradiated with UV light, so that the exposure time becomes longer as approaching the center. Therefore, the irradiation amount of the UV light to the film 2 increases as it approaches the center, but in order to prevent this, as shown in FIG. 3, the opening 9 is formed into a sector shape that becomes narrower as it approaches the rotation center.

As shown in FIGS. 4 and 5, a circular opening 16 is formed at the center of rotation.
Is provided so as to be continuous with the opening 9, and a filter 17 such as glass for reducing the transmittance of UV is incorporated in the opening 16.
The irradiation amount of UV light may be uniform over the entire area of the wafer 1 in some cases. Although the embodiment shows a case where one UV lamp 14 is used, there may be a case where two or more lamps 14 are 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. In this case, the area mask 11 is also rotated together with the lamp 14.

[0022]

【The invention's effect】

According to the present invention, as described above, an ultraviolet-curable adhesive film is attached to the surface of a wafer, a UV lamp serving as an ultraviolet irradiation unit is disposed eccentrically with respect to the center of the wafer, and the wafer or the ultraviolet irradiation unit is turned. Irradiates the UV light over the desired area of the wafer, and the UV light shorter than the diameter of the wafer makes it possible to uniformly irradiate the entire surface of the wafer with UV light. Therefore, the size of the entire apparatus can be reduced.

In the case where a mask having a fan-shaped opening in which the center of the wafer is narrowed is provided between the wafer and the ultraviolet irradiation means,
Since UV light can be uniformly applied to the entire surface of the wafer,
This is effective when it is necessary to prevent the UV light from hitting the center of the wafer too much.

In the ultraviolet irradiation apparatus, the method of the first invention can be performed, and the wafer can be uniformly irradiated with UV light.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing an embodiment of the present invention.

FIG. 2 is a partially cutaway plan view showing each example of the same area mask.

FIG. 3 is a partially cutaway plan view showing each example of the same area mask.

FIG. 4 is a partially cutaway plan view showing each example of the same area mask.

FIG. 5 is a sectional view taken along line IV-IV in FIG. 4;

[Explanation of symbols]

 1 Silicon wafer 2 Adhesive film 9 Opening 11 Area mask 14 UV lamp 16 Opening 17 Filter

Claims (3)

(57) [Claims] 1. A wafer to which a film is attached in a processing step of attaching a film having a pressure-sensitive adhesive layer having a property of decreasing adhesive strength by ultraviolet irradiation to a wafer for forming an electronic circuit and performing desired processing. UV light irradiating means is eccentrically arranged, the wafer or the UV light irradiating means is turned, the irradiation of the UV light is restricted according to the position in the wafer, and the UV light is uniformly irradiated over a desired range of the wafer. A method for irradiating ultraviolet rays, characterized in that: 2. A wafer to which a film is attached in a processing step of applying a film having a pressure-sensitive adhesive layer having a property of reducing adhesive strength by ultraviolet irradiation to a wafer for forming an electronic circuit and performing desired processing. The ultraviolet irradiation means is eccentrically arranged with respect to the wafer, and a mask having a fan-shaped opening in which the center side of the wafer is narrowed is provided between the wafer and the ultraviolet irradiation means. An ultraviolet irradiation method characterized in that the ultraviolet irradiation means and the mask are stopped by turning, or the ultraviolet irradiation means is turned together with the mask to stop the wafer, so that uniform ultraviolet irradiation is performed from the center to the periphery of the wafer. 3. An ultraviolet irradiation apparatus for applying a film having a pressure-sensitive adhesive layer whose adhesive strength is reduced by ultraviolet irradiation to a wafer for forming an electronic circuit and performing desired processing. The ultraviolet irradiation means is eccentrically arranged with respect to the wafer, the wafer or the ultraviolet irradiation means is turned by the turning means, and the ultraviolet light is transmitted to the wafer through the restricting means for restricting the irradiation of the ultraviolet light according to the position in the wafer. An ultraviolet irradiation apparatus characterized in that the irradiation is performed uniformly over the range of (1).