JPH03203233A - Releasing method of wafer - Google Patents

Abstract

PURPOSE:To achieve release simply and positively in a short time and automation of release without producing any deterioration of a wafer by allowing a pressed fluid from the rear side of a plate into a small hole and by releasing the wafer which is attached to the plate from the plate by the fluid pressure. CONSTITUTION:An attaching part 1a for sucking or adhering a wafer is provided on the surface of a plate 1 and small holes 1b are penetrating through the plate 1 at the attaching part 1a. Then, a pressure fluid is allowed to flow from the rear side of the plate 1 to the small hole 1b and the wafer which is attached to the plate 1 due to surface tension or vacuum suction is released from the plate 1 due to the fluid pressure, thus enabling release to be performed by the pressure fluid and the fluid to be supplied from the rear surface of the wafer, thereby preventing the wafer from being contaminated and damaged on release, improving work reliability since no works are performed manually, and achieving automation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for peeling a semiconductor wafer adsorbed or adhered (hereinafter collectively referred to as "adhesion") onto a plate.

(Prior Art) For example, during mirror polishing, a semiconductor wafer (hereinafter simply referred to as an "R wafer") is attached onto a plate made of ceramic or the like. As attachment means, a method of applying an adhesive and adhering by heating, or a method of adsorption is used, but in either case, the work of separating the wafer from the above-mentioned plates 1 to 1 after mirror polishing is very troublesome. .

Conventionally, Japanese Utility Model Application Publication No. 1-89747 and Japanese Patent Application Publication No. 1-93
As seen in Japanese Patent No. 126, manual work using a special peeling jig was required.

(Problem to be solved by the invention) However, the above-mentioned wafer is extremely thin with a thickness of 0.7 mm or less and is difficult to handle.The mirror surface does not allow even minute scratches, so careful handling is required. The shape and specifications of handling jigs,
There are restrictions on materials, etc. Therefore, manual peeling work using the above-mentioned jig requires skill and takes a lot of time. The above-mentioned peeling process is considered to be a process that is difficult to automate.

However, in the above-mentioned Japanese Patent Application Laid-Open No. 1-93126,
Without using a jig, the semiconductor wafer is exposed to a 1500G jet of silicone oil with a temperature controlled temperature, the adhesive layer is thermally softened, and the wafer is peeled off from the inclined plate surface by sliding under its own weight and the force of the jet. A technique for performing this has been disclosed. This method of spraying the wafer with a jet of silicone oil heats the surface of the wafer at a relatively high temperature in the atmosphere, which is undesirable because it causes contamination (oxidation, adhesion of fine particles, etc.) on the surface. In addition, the above-mentioned technique does not directly thermally soften the adhesive, but rather indirectly thermally softens the adhesive through the wafer, so its effects cannot be expected to be very promising.

Under the above circumstances, the present invention was made with the object of proposing a wafer peeling method that can perform peeling easily and reliably in a short time, does not cause wafer deterioration, and can realize automation of peeling. .

(Means for Solving the Problems) The first invention of the present application is to form a microhole penetrating the front and back sides of the plate in advance in the wafer attachment part, and to flow pressure fluid into the microhole from the back side of the plate to A wafer attached to a plate by tension or vacuum adsorption is peeled from the plate by fluid pressure, and the second invention of the present application is to separate the wafer from the plate by using fluid pressure. then pressurized cooling fluid flows into the microholes from the back side of the plate to cool the adhesive layer of the wafer attached to the plate with adhesive, causing the adhesive layer to change in volume. The wafer attached to the plate is peeled off from the plate by the fluid pressure by causing damage to the adhesive layer, and the third invention of the present application is to form a microhole that penetrates the front and back sides of the plate in advance in the wafer attachment part of the plate. is formed in advance, and while flowing pressure fluid into the microholes from the back side of the plate and spraying the fluid onto the top surface of the wafer, the wafer attached to the plate is peeled off from the plate by the fluid pressure of the fluid from the microholes. It is something to do. Here, vacuum adsorption mainly refers to the case where when the wafer comes into contact with the plate via a liquid other than adhesive, the pressure between the two becomes less than atmospheric pressure, and the wafer is attached to the plate. be.

(Function) The wafer that has been polished is transported to the vicinity of the wafer carrier together with the plate, where the open end of the fluid feed pipe is connected airtightly or watertightly to the portion of the microhole on the back surface of the plate.
From here, cooled air or liquid is forced under pressure. According to the first invention of the present application, due to the pressure action of the fluid, and according to the second invention of the present application, the adhesive layer is cooled to cause a volume change, and further according to the third invention of the present application, In combination with the fluid being sprayed onto the top surface of the wafer, the wafer attached to the plate is peeled off from the plate.

(Example) Hereinafter, the present invention will be explained based on the accompanying drawings.

FIG. 1 is a cutaway view showing an embodiment of the present invention, and FIG. 2 is an enlarged plan view of the plate.

As shown in these figures, the surface of the plate 1 is provided with an adhesion part 1a on which the wafer 2 is to be attracted or adhered, and the adhesion part 1a has micro holes 1b penetrating the front and back sides of the plates 1 to 1. It is formed.

In addition, when the diameter of the wafer is about 76 mm to 200 mm, the diameter of the microholes is about 0.5 to 1.5 mm, and the number of micropores is about 5.
~12 pieces is preferable. This is because, as will be described later, pressure fluid is supplied from the hole 1b, so if the hole 1b is large, the pressure applied to the wafer will be large, which is undesirable as it will have an adverse effect on the wafer.

FIG. 1 shows a peeling method in the case of an adhesive mode in which a wafer 2 is temporarily attached to the attached portion 1a of the plate 1 with an adhesive, and the adhesive is further solidified by heating. 3 indicates a solidified adhesive layer. in this way,
If the wafer 2 is firmly attached to the plate 1, it cannot be separated simply by applying fluid pressure to the back surface of the wafer 2 through the microhole 1b from the back surface of the plate 1.

Therefore, in such a case, strain fracture is caused in the adhesive layer 3 using a weight of volume change due to temperature change, and fluid pressure is applied under this state.

That is, the open end of the fluid feed pipe 4 is airtightly or watertightly connected to the back surface of the attachment part 1a of the plate 1, and cooled air or liquid (hereinafter referred to as "cooling fluid 5") is applied under pressure. The fluid is sent to the feed pipe 4. Thus, cooling fluid 5
When the adhesive layer 3 reaches the back surface of the plate 1, the adhesive layer 3 is cooled and a volume change occurs.

The wafer 2 is now in a state where it can be peeled off from the plate 1 with a small amount of force. The wafer 2 is then separated from the plate 1 by the pressurized cooling fluid 5.

In the embodiment, in order to prevent the wafer from jumping at the moment of separation, a fluid 7 such as air or water is sprayed onto the upper surface of the wafer 2 from a nozzle 6, and the plate 1 is tilted to slide and transfer using its own weight and the pressure of the fluid 7. It is structured as follows. 8
9 indicates a support member for the nozzle 6, 9 indicates a chute made of Teflon or the like, and 1o indicates a carrier. In this way, when it is decided to spray the fluid 7 onto the upper surface of the wafer 2, the carrier 1
Regarding the transfer of the wafer to the wafer, it has been possible to appropriately roll the wafer to the desired controller 1.

However, if the attachment of the wafer 2 to the plate 1 is based on surface tension or vacuum adsorption, it is sufficient to simply feed the pressure fluid 5a to the fluid feed pipe 4. In this case, the adhesive layer 3 does not exist in FIG. 1.

FIG. 3 shows a case where a template 11 is used for the plate 1, and this template 11 allows the attachment and positioning of the wafer 2 to be reliably determined.

(Effects of the Invention) As explained above, according to the present invention, separation, which was conventionally performed using a jig, can be performed using pressure fluid or cooling fluid, and such fluid is supplied from the back surface of the wafer. The present invention has many advantages, such as avoiding contamination or damage to the wafer during stripping, and since it does not require manual labor, the work is reliable and can be automated. It is something.

[Brief explanation of drawings]

FIG. 1 is a cutaway front view showing an embodiment of the present invention, FIG. 2 is an enlarged plan view of the plate, and FIG. 3 is a sectional view of the plate portion using a template. 1... Plate 1b... Microhole 3... Adhesive layer 5a... Pressure fluid

Claims (3)

[Claims] (1) A microhole is formed in advance in the wafer attachment part of the plate, and a pressure fluid is flowed into the microhole from the back side of the plate, and the wafer attached to the plate is removed from the plate by the fluid pressure. A wafer peeling method characterized by peeling. (2) A microhole is formed in advance in the wafer attachment part of the plate, and the cooling fluid is poured into the microhole from the back side of the plate while being pressurized. The adhesive layer is cooled to change the volume of the adhesive layer, the volume change causes destruction of the adhesive layer, and the wafer attached to the plate is separated from the plate by fluid pressure. wafer stripping method. (3) A microhole penetrating the front and back sides of the plate is formed in advance in the wafer attachment part of the plate, and while pressure fluid is poured into the microhole from the back side of the plate, the fluid is sprayed onto the top surface of the wafer and the wafer is attached to the plate. A wafer peeling method characterized in that the wafer is peeled from the plate by the fluid pressure of the fluid from the microholes.