JPH04270083A - Laser trimmer device - Google Patents

Abstract

PURPOSE:To uniformly trim the wafer by constantly maintaining the laser output with quick response. CONSTITUTION:The laser light which is set to the prescribed output with the variable deflection plate 4 is introduced to the optical laser by the prescribed rate with the transmissible and reflective mirror 11, this introduced laser light is transformed to the signal with the output detector 10, the control power source 12 controls variably the electric field of the light modulation unit 2 with this transformed signal, so the output laser is stabilized.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser trimmer device used in a redundant circuit correction process or in trimming a resistor part in a semiconductor manufacturing process.

0002

2. Description of the Related Art FIG. 2 is a block diagram of a conventional laser trimmer device. Conventionally, this type of laser trimmer device, as shown in FIG. 2, includes a laser oscillator 1 that generates laser light, an optical modulator 2 that functions as a shutter to block the emitted laser light, and a laser trimmer that adjusts the peak phase of the laser light. A variable deflection plate 4 that selectively adjusts and attenuates the output, a pair of reflecting mirrors 5 that corrects the optical axis of the laser beam, and a shielding plate that determines the diameter of the laser spot irradiated onto the surface of the wafer 9 mounted on the stage 8. It had 6.

[0003] When using this laser trimmer device to trim and correct the redundant circuit formed on the surface of the wafer 9, the wafer is first mounted on the stage 8, and the stage 8 is first moved. , the output measuring device 7 adjacent to the stage 8 is positioned at the laser beam irradiation position.

Next, the output measuring device 7 is irradiated with a laser beam, the output of the irradiated laser beam is measured, and it is determined whether the output value is suitable or not. If the laser light output is not accurate, the variable deflection plate 4 is controlled to adjust the output to the desired output. In this way, the redundant circuit is trimmed.

[0005]

[Problem to be Solved by the Invention] In the conventional laser trimmer device, after the laser output is set in the pre-trimming preparation work, the settings of the variable deflection plate and the pulse oscillation controller are held constant. The stability of the laser output on the stage during processing is directly affected by variations in the output of the laser oscillator over time, and redundant circuits within the wafer may not be formed or other functional elements may be destroyed due to excessive output. There was a problem.

An object of the present invention is to provide a laser trimmer device that solves this problem.

[0007]

[Means for Solving the Problems] The laser trimmer device of the present invention includes a transparent reflective mirror disposed in an optical path after a variable deflection plate that sets a laser beam oscillated from a laser oscillator to a predetermined energy; an output detector for detecting a laser output from which a fixed ratio of the laser output set by the transparent reflective mirror is derived; and a signal converted by this output detector is inputted and applied to an optical modulator. and a control power source that controls the electric field generated.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a laser trimmer device according to the present invention. This laser trimmer device includes a transparent reflective mirror 11 provided in the laser optical path after the variable deflection plate 4, and an output detector 10 that measures the light intensity of the laser beam reflected from the transparent reflective mirror 11. A control power source 12 is provided which compares the output signal of the output detector 10 with a reference signal and controls the voltage applied to the optical modulator 2. Other than that, it is the same as the conventional example.

The operation of this laser trimmer device is as follows:
The output measuring device 7 is temporarily irradiated with a laser beam, and the output measuring device 7 is
The laser output is measured, and the angle of the variable deflection plate 4 is controlled based on the output measurement value to set the laser output. next,
During the trimming process, the light is divided by a transparent reflector 11 placed after the reflector 5 for correcting the optical axis of the laser beam irradiation optical path, such as a half mirror, and a fixed ratio of the laser output is sent to the output detector 10. Extract the laser light. Next, the output signal converted from the incident light of the output detector 10 is sent to the control power supply 12.
is input, the control power supply 12 compares it with a reference signal, superimposes a predetermined voltage on the voltage of a set power supply (not shown), and outputs it to the optical modulator 2.
to be applied. This changes the electric field applied to the optical modulation element of the optical modulator 2 and controls the laser output.

[0011] In this way, the laser is oscillated, the output of the laser beam is detected while being trimmed, and fluctuations in the output of the laser beam are fed back to the optical modulator 2, thereby maintaining the laser output constant with a quick response.

0012

[Effects of the Invention] As explained above, the present invention divides the laser light emitted from the laser oscillator at an arbitrarily set ratio, extracts it from the irradiation laser optical path, and detects the extracted laser light output at a fixed ratio. A laser trimmer device that can maintain a constant laser output and stably trim redundant circuits formed on a wafer by controlling the electric field applied to the optical modulator using the output detector and the signal from this output detector. There is an effect that can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a laser trimmer device showing one embodiment of the present invention.

FIG. 2 is a block diagram of a laser trimmer device showing a conventional example.

[Explanation of symbols]

1 Laser oscillator 2. Optical modulator 3, 5a, 5b Reflector 4 Variable deflection plate 6. Shielding board 7 Output measuring device 8 Stage 9 Wafer 10 Output detector 11 Transparent reflective mirror 12 Control power supply

Claims (1)

[Claims] 1. A transparent reflective mirror disposed in an optical path after a variable deflection plate that sets a laser beam oscillated by a laser oscillator to a predetermined energy, and the laser output set by the transparent reflective mirror. includes an output detector that detects a laser output derived by a fixed ratio of the output of the optical modulator, and a control power source that inputs a signal converted by the output detector and controls the electric field applied to the optical modulator. A laser trimmer device featuring: