JPS5994596A - Fusion cutting device by laser - Google Patents

Abstract

PURPOSE:To operate a titled device at a high speed with high accuracy by mounting only the objective optical system on an X-Y table which positions an optical axis in X-Y coordinates thereby decreasing the loading weight and reducing the size and weight of said table. CONSTITUTION:A laser beam L oscillated from a laser oscillator 21 is collimated 22 to parallel luminous fluxes having a large diameter and thereafter the fluxes pass a filter 23 and are thus made uniform in intensity distribution. The parallel luminous fluxes which are made uniform in itensity distribution are reflected at a right angle by a mirror 24 and are cast to an objective optical system 25. The system 25 consists of an aperture 26 and an objective 27, and part of the parallel luminous fluxes having the uniform intensity distribution cast from the mirror 24 is conducted via an aperture 26 to the lens 27. The laser beam L stopped down by the lens 27 is always constant in energy and can be cut stably by fusion. A wafer 28 is placed on an XYtheta table 29 and is moved between chips.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a fuse blowing device using a radar that switches between a defective element and a spare element on a semiconductor wafer by blowing a fuse.

[Technical background of the invention and its problems]

As a means for providing redundancy to chips, a technique is known in which a spare element is provided on a wafer and the defective element and the spare element are switched by blowing a fuse. There are two methods for blowing out the fuses: an electric blowing method and a radar blowing method. Although two inserting pads are required, the latter is often used because it eliminates the need for a gap and allows for a much smaller chip size.

FIGS. 1 and 2 show a conventional radar fuse blowing device, where 1 is a pace. An XY table 2 is provided on this pace 1. The X table 3 of the XY table 2 is connected to an X direction linear motor 4, and the Y table 5 is connected to a Y direction linear motor 7 via a connection table 6. On the other hand, 8 is a YAG Rade head, and the Rade beam L oscillated by this YAG Rade head 8 is collimated by a collimator 9, bent at a right angle by a mirror 1o, and is incident on a mirror 1 installed on the X table 3. It looks like this.

The Lede beam L reflected by this mirror 11 is bent by a mirror 12 installed at the tip of the Y table 5 and guided to an objective lens 13. The light condensed by this objective lens 13 is condensed to a diameter of 10 μm or less at the focal point, and is designed to blow out minute fuses arranged in each chip on the Ueno 14. This wafer 14 is placed on an XYθ table 15, and each time a predetermined fuse in the chip is blown, the XYθ table 15 performs a step and repeat operation for one chip, and the process for the fuse in the next chip is as follows:
The upper XY table 2 that drives the objective lens 13 is at high speed.

It is designed to move with high precision.

By the way, in the conventional fuse blowing device, the objective lens 13
The optical axis of can be quickly moved to any xy coordinate.

In order to position with high precision, the mirrors 11 and 12 and the objective lens 13 must be moved at the same distance at the same time.
There will be no people unless they are operated at the same distance at the same time. Therefore, in order to move these optical systems at high speed and with high precision, the table on which they are placed, that is, the XY table 2, needs to be very rigid, and the weight of the movable parts of the l-axis wheel is around 10 Kf even if it is made of aluminum. It has become.

For this reason, even if linear motors 4 and 7 are used, there is a limit to how high the speed can be increased, and even in terms of high precision, their size is susceptible to environmental changes, such as vibration and temperature changes, and the mounting location of scales etc. There were problems such as restrictions on

[Purpose of the invention]

This invention was made based on the above circumstances, and its purpose is to be able to position an optical axis at a predetermined position on a wafer at high speed and with high precision, and to make the device smaller and lighter. The present invention attempts to provide a fuse blowing device using a laser.

[Summary of the invention]

This invention is equipped with only an objective optical system consisting of an xyY table arrangement that positions the optical axis on the XY coordinates and an objective lens, which greatly reduces the weight mounted on the XY table and makes the XY table compact.

The weight reduction lies in the fact that it can be operated at high speed and with high precision, as shown in Fig. 9.

[Embodiments of the invention]

The present invention will be described below based on an embodiment shown in the drawings. In FIG. 3, reference numeral 21 denotes a laser oscillator consisting of a YAG radar head, and the laser beam oscillated from this laser oscillator 21 is made into a large-diameter parallel beam by a collimator 22 and then transmitted through a filter 23.

The concentration distribution of this filter 23 corresponds to the output distribution of the laser beam L, and the transmitted laser beam L has a uniform intensity distribution. This parallel light beam with a uniform intensity distribution is reflected at right angles by a mirror 24, and is incident on an objective optical system 25, which will be described later. This objective optical system 25 consists of an aperture 26 and an objective lens 27, which are mounted on the XY table 2 and positioned on the XY coordinates in the same way as the conventional fuse blower shown in FIG. There is. And the mirror 24
A part of the parallel light flux with a uniform intensity distribution reflected from the
The light is guided to an objective lens 27 via a mother char 26, and is condensed to 10 μm or less by this objective lens 27. The optical energy of the Lede beam L focused by the objective lens 27 is always constant, and stable fuse blowing is possible. It should be noted that the wafer 28 is placed on an XYθ table 29 in the same manner as in the prior art, and can be moved between chips.

In this way, the objective optical system 2 installed on the XY table
5 is made of two parts, the armature 26 and the objective lens 27, and can be manufactured within a moving weight of 2 Kq per axis.

〔Effect of the invention〕

As explained above, in this invention, only the objective optical system is
Since it is configured to be mounted on a table and to perform XY coordinate positioning, the weight mounted on the XY table can be significantly reduced, and the XY table can be made smaller and lighter.

Therefore, it is possible to perform high-speed and high-precision operations in the X and Y directions.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional fuse blower, FIG. 2 is a perspective view of an optical system, and FIG. 3 is a perspective view of an embodiment of the present invention. 21... Rade oscillator, 25... Objective optical system, 28
...Wafer, 29...XYθ table.

Claims (1)

[Claims] A fuse blowing device using a Rade that switches by blowing defective elements and spare element traffic on a wafer includes an optical system that converts the Rade beam oscillated from a Rade oscillator into a parallel beam and then flattens the intensity distribution, and an optical system that flattens the intensity distribution. An XY table for mounting an objective optical system connected to the objective optical system and positioning the optical axis of the objective optical system on the XY coordinates, and an XYθY table 5 provided opposite to the objective optical system and on which the wafer is placed. Fuse blowing device by Rede.