JPS6030148A - Evaluating method of adhesion of thin-film - Google Patents

Abstract

PURPOSE:To apply even samples for an evaluation to products, and to evaluate the adhesion of a thin-film easily without requiring special operating time by spraying water against the surface of the thin-film formed on a substrate in a beam shape and evaluating the adhesion of the thin-film by the magnitude of hydraulic pressure through which an exfoliation is generated. CONSTITUTION:A spindle 1 to which a wafer 4 is fitted is turned, and the wafer 4 is scanned up to an end from the end of the wafer while beam-shaped high- pressure water 5 discharged from a nozzle 6 is sprayed. The wafer 4 is hydro- extracted by the increase of the revolution of the spindle 1, the wafer 4 is removed, and the state of peeling of a thin-film is observed. The work functions as a washing process in a manufacturing process for the wafer 4 in combination. High-pressure water such as one at 25kg/cm<2> is sprayed against the thin-film, and the adhesion of the thin-film is regarded as acceptable one when the thin- film is peeled by less than 5mm. from the outer circumference of the wafer and as defective one when the thin-film is peeled by 5mm. or more, and acceptable or defective adhesion can be discriminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for evaluating the adhesion of a thin film formed on a wafer.

(bl Technology Background In the production of chips for hybrid integrated circuits and bubble memories, the thick film formed on the substrate generally has a strong adhesion between the substrate and the thick film, so there is no need to be particularly careful about peeling the film.
Thin films formed on a wafer as a substrate, especially 5i
Ni-F formed on the 02 wafer as a substrate
E-based thin films have low adhesion, and it is necessary to continuously monitor changes in adhesion during the process of forming the thin film. Applying a destructive testing method to such continuous evaluation is not a preferable method because it requires a lot of work time for evaluation and also reduces the yield of the product. It is desired to apply an adhesion evaluation method that sets an allowable limit for adhesion, and if the adhesion of the evaluation sample is greater than or equal to the allowable limit, it can be applied to products, and that does not require special work time for evaluation. There is.

(11,) Prior Art and Problems A method called cross-cut resistance evaluation is generally used to evaluate the adhesion of thin films. Cut vertically and horizontally with a cutter to form a plurality of thin films arranged in the shape of an outlet, and when the adhesive tape stuck thereon is not peeled off, the outlet peels off along with the adhesive tape. The adhesion of the thin film is evaluated by the quantity ratio of . However, this method is a destructive test, and evaluation samples cannot be used for production. Further, it takes a lot of time and skill to make vertical and horizontal cuts with a cutter and form a plurality of thin films having the same size.

As a simplified method for evaluating cross-cut resistance, the process of forming multiple thin films of the same size is omitted, and the process of peeling off the attached adhesive tape is repeated several times.
There is a method of evaluating the adhesion of the thin film by observing the state of the thin film that peels off together with the adhesive tape at that time. Although this method cannot strictly evaluate the cross-cut resistance described above, a correlation with the cross-cut resistance evaluation is recognized, and the adhesion of the thin film can be evaluated using this result as an acceptable limit. This method has the advantage that samples for evaluation can be used for products, and that the work time required for evaluation is reduced by the time required to make vertical and horizontal cuts with a cutter, and no skill is required. However, even with this method, it takes time to evaluate the adhesion of the thin film, and the problem is that the surface of the thin film may be damaged, reducing yield.

(d) Purpose of the invention The purpose of the present invention is to provide a method for evaluating adhesion that allows evaluation samples to be used in products, does not require special work time for evaluation, and can be easily evaluated by anyone. It's about doing.

(el) The structure and purpose of the invention is to spray a beam of water onto the surface of a thin film formed on a substrate by a method such as vapor deposition, sputtering, coating, etc., and to separate the thin film by the magnitude of the water pressure that causes the thin film to peel. This is achieved by evaluating adhesion.

(“) Examples of the invention The present invention will be explained in detail below with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of the present invention.

In FIG. 1, a spindle 1 consists of a rotary table 2 and a rotary shaft 3, and the surface of the rotary table 2 has a number of holes for vacuum suctioning the wafer 4, and the other end of the hole is opened. are integrated in the rotary table 2, and are connected to a vacuum device (not shown) through the center of the rotary shaft 3. On the other hand, the nozzle 6 that discharges the beam-shaped high-pressure water 5 is
It is fixed to a mechanical part (not shown) that can maintain an angle α with the surface of the wafer 4 and scan the range indicated by the arrow 7.

The evaluation of the thin film adhesion using the above equipment is as shown in Figure 2 (the spindle 1 to which the wafer 4 is attached is rotated and tightened, and a beam of high-pressure water 5 discharged from the nozzle 6 is sprayed from one end of the wafer 4 to the other. After completing the scanning, the wafer 4 is removed from the spindle 1 and the wafer 4 is removed from the spindle 1 to remove the thin film. This operation also serves as a cleaning step in the manufacturing process of wafer 4, and if this operation is incorporated, the cleaning step may be omitted.

FIG. 3 is a diagram showing a chip forming area on a wafer.

The area 8 forming the chi knob on the surface of the wafer 4 is at least 5 mm from the outer periphery of the wafer 4 at the outermost point. It is empirically known that peeling of a thin film formed on a wafer starts from the outer periphery, and the smaller the adhesion strength, the further the peeling goes to the inside. Therefore, the permissible limit may be set within a range in which peeling of the thin film does not reach the chip forming area 8, that is, within 5 mm from the outer circumference of the wafer.

FIG. 4 shows an example of data obtained when the above evaluation was performed on five types of wafers.

High-pressure water is discharged from a nozzle that forms a 60 degree angle with the wafer surface and has a hole with a diameter of 0.1 mm to the wafer, which rotates at 500 revolutions/minute, and scans at a rate of 1 time/2 seconds. The solid line represents the pressure of high-pressure water when the thin film reaches positions 2 mm and 5 mm from the outer periphery of the wafer 4.
~5 mm, the dashed line indicates the pressure when it is 5 mm or more.

Figure 5 similarly shows that on five types of wafers, the process of forming multiple thin films of the same size is omitted, and the process is repeated several times without peeling off the adhesive tape. This is an example of an evaluation conducted by observing the state of the thin film peeling off together with the tape and evaluating the adhesion of the thin film.

In Figure 4, the peeling of the thin film is 2 to 5 minutes from the outer periphery of the wafer.
The diagram showing the pressure of high-pressure water when reaching the mm position is similar to FIG. 5, with wafer A having a low level and the other wafers having high levels.

Therefore, high-pressure water at an intermediate pressure of 25 kg/cJ is sprayed onto the thin film, and if the thin film peels off less than 5 mm from the outer circumference of the wafer, it is considered good, and if it is 5 mm or more, it is judged as bad, and it is determined whether the adhesion is good or bad. can do.

(gl Effects of the Invention As described above, according to the present invention, samples for evaluation can be used for products, and in addition, no special work time is required for evaluation, and adhesion strength can be easily evaluated by anyone. Evaluation methods can be provided.

[Brief explanation of drawings]

1 and 2 are examples of the present invention, FIG. 3 is a diagram showing a chip formation range on a wafer, and FIGS. 4 and 5 are examples of test data. In the figure, 1 is the spindle, 2
3 is a rotating table, 4 is a wafer, 5 is high pressure water, 6 is a nozzle, and α is the angle of the nozzle.

Claims (1)

[Claims] A thin film adhesion evaluation method in which a beam of water is sprayed onto the surface of an M film formed on a substrate by a method such as vapor deposition, sputtering, coating, etc., and evaluation is performed based on the magnitude of the water pressure that causes the thin film to peel.