JPS62281438A - Manufacture of integrated circuit - Google Patents

Abstract

PURPOSE:To eliminate the possibility of laser restricting a working range for trimming and thus permitting chips to be identified by quality marks in a short time by performing the marking which is obteined according to quality of chips, thereby transferring ink to a wafer and applying laser beams to a thermal transfer film placed on the wafer. CONSTITUTION:A manufacture of IC circuit comprises two processes; one of them is a trimming process where laser beams are applied to a pattern formed on e wafer 2 to perform trimming and the other one is a marking process where the marking is cerried out eccording to the quality of the chips and then, in the manufacture of IC circuit, the above marking is performed as follows: a thermal transfer film 8 is put on the wafer 2 and ink of the film 8 is transferred to the wafer 2 after applying the laser beams to the film 8. For instance, trimming and quality judgement are carried out by using a laser trimmer and when defective chips are detected, the thermal transfer film 8 is placed on the wafer 2 according to CPU 7 and the. laser beams are applied on the film 8. As a result, the laser beams dissolve ink of the film 8 and transfer it on the wafer 2, resulting in having a defective mark on the wafer.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an improvement in marking whether a chip is good or bad in a method of manufacturing an integrated circuit.

[Prior Art] Some integrated circuit manufacturing methods involve trimming by irradiating a wafer pattern with laser light.

A device used for such trimming is a laser trimmer. FIG. 2 shows an example of the configuration of a laser trimmer.

In the figure, 1 is a stage on which a wafer 2 is placed.

Reference numeral 3 denotes a measuring section, which measures the resistance value at any time during the trimming operation, for example, when the object to be trimmed is a resistance value.

Reference numeral 4 denotes a probe card, which determines the portion of the wafer 2 to be trimmed.

Reference numeral 5 denotes a laser, and the emitted light is reflected by a mirror 6 and irradiated onto the wafer 2 .

7 is a CPU, which controls the driving of the measuring section 3 and the laser 5, and also controls the positioning of the stage 1 and the mirror 6.

With such a laser trimmer, the laser 5 and the stage 1 are positioned by a control signal from the CPU 7. In the trimming operation, for example, when trimming a resistor, the measuring unit 3 measures the resistance, and the laser beam is used to cut the resistance to drive the resistance value to a target value. Then, based on the measurement signal from the measurement section 3, the CPU 7 determines whether the chip is good or bad.

If the chip is defective, it must be marked as defective.

Conventionally, marking has been performed by applying an input force 1 (hand for applying ink ffl) to a laser trimmer, for example, as shown by the broken line in the figure.

However, applying an input force limits the operating range of the laser, which may cause problems in trimming. In addition, a baking process is required to dry the applied ink, resulting in the problem that manufacturing takes time.

The present invention has been made in order to eliminate the above-mentioned problems, and is capable of manufacturing integrated circuits that can mark chips as good or bad in a short time without restricting the operating range of the laser during trimming. The purpose is to realize the method.

[Means for Solving the Problems] The present invention includes a step of irradiating a pattern formed on a wafer with a laser beam to perform trimming, and a step of dividing the wafer and marking the resulting chips according to whether they are good or bad. In the method for manufacturing an integrated circuit including a step, the marking is performed by placing a thermal transfer film on the wafer, irradiating the thermal transfer film with the laser light, and transferring the ink of the thermal transfer film to the wafer. A method for manufacturing an integrated circuit, characterized by:

[Example] Hereinafter, the present invention will be explained using the drawings.

FIG. 1 is a diagram showing an example of the configuration of a laser trimmer for carrying out the present invention. Components in FIG. 1 that are the same as those in FIG. 2 are given the same reference numerals.

In FIG. 1, reference numeral 8 denotes a thermal transfer film, which is a feature of the present invention, and is placed on the wafer 2 as shown in the figure when marking is performed. The placement and movement of the thermal transfer film 8 is controlled by the CPU 7.

Using such a laser trimmer, trimming and quality judgment are performed in the same manner as the laser trimmer shown in Fig. 2 described above.
If a defective chip is detected, a thermal transfer film 8 is placed on the wafer 2 by the CPU 7. This thermal transfer film is then irradiated with laser light. As a result, the ink on the thermal transfer film 8 is melted and transferred onto the wafer 2, and a defective mark is attached.

In addition, in the example, the case where a mark is attached only when the product is defective has been explained, but this is not limited to this. Even if the mark is attached only when the product is non-defective, it is possible to mark the product only when the product is non-defective and the product is defective. You may also add a mark.

[Effects] According to the present invention, since the thermal transfer film is placed on the wafer only when marking is to be done, it is possible to mark the chips for identification of pass/fail without restricting the movement range of the trimming laser.

Furthermore, since marking is performed by thermal transfer recording, there is no need for a step of drying the ink, making it possible to perform marking in a short time.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a configuration example of a laser trimmer for implementing the present invention, and FIG. 2 is a configuration diagram of a conventional example of a laser trimmer. 2... Wafer, 3... Measuring section, 5... Laser, 7
...CPU, 8...Thermal transfer film.

Claims (1)

[Claims] In a method for manufacturing an integrated circuit, the method includes a step of irradiating a pattern formed on a wafer with a laser beam for trimming, and a step of dividing the wafer and marking the resulting chips according to whether they are good or bad. . A method for manufacturing an integrated circuit, which is carried out by placing a thermal transfer film on the wafer, irradiating the thermal transfer film with the laser beam, and transferring the ink of the thermal transfer film to the wafer.