JPS5933971B2 - Circuit pattern forming method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of forming a circuit pattern on a resist coated on a wafer.

Conventionally, a photoetching method using a photoresist has been used for fine photoetching, and circuit patterns have been formed by processes such as mask contact exposure and development. However, photoresists are limited to those that are photosensitive, and exposure requires a full-size negative (or positive) mask such as a chrome mask or silver salt emulsion mask, and development mainly uses organic solvents, so handling is difficult. , development conditions, the toxicity of organic solvents to the human body, disposal of used solutions, etc. were troublesome. SUMMARY OF THE INVENTION An object of the present invention is to provide a circuit pattern forming method that eliminates the drawbacks of the prior art described above, allows for easy pattern design changes, and prevents pollution caused by organic solvents.

That is, the present invention directly irradiates a resist coated on a substrate with focused laser light, evaporates and removes the irradiated resist portion with high energy, and forms a circuit pattern on the resist with the substrate exposed. It is characterized by forming.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The process of forming a mask pattern, that is, a resist pattern, in manufacturing a silicon diode according to an embodiment of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a sectional view showing a resist applied to the wafer. As shown in the figure, a resist 4 which is a mask
is coated on a wafer 1 3 in which silicon dioxide 2 is formed on a silicon substrate 1, and this resist 4
Any liquid may be used as long as it is acid-resistant and cannot be dissolved by acidic chemicals such as hydrogen fluoride-based chemicals so as to remove the myricon dioxide from only the portions of the resist that do not remain. That is, the resist may be made of, for example, polyisoprene, polystyrene, polyvinyl chloride, polyethylene, phenol, vinyl chloride, polyester, nylon, or the like. Next, a laser processing apparatus for removing a portion of this resist to form a pattern as shown in FIG. 2 will be explained in detail with reference to FIG. 3.

That is, the laser processing apparatus includes a laser oscillator 5 and a driver 6 for causing the laser oscillator 5 to acousto-optically pulse oscillate.
, a pulse generator 7, a modulator 9 for turning the laser beam 8 into 0N and 0FF during continuous oscillation, a scanning optical system 10 for scanning the laser beam with a rotating prism, and a convex lens for condensing the laser beam. an X-Y table 12 on which a resist-coated wafer is placed and moves in two axes;
It consists of a motor 13 for driving the table, a pulse generator 7, a modulator 9, a scanning optical system 10, and a numerical control device 14 for controlling the motor 13. As the laser oscillator 5, an Ar ion laser oscillator is used, which has a quick response due to cavity damping and can provide a pulsed laser beam with a short pulse width.

The wafers 1 and 3 placed on the X, Y table 12 are moved together with the XY table 12 by driving the motor 13 in response to a command signal from the numerical control device 14. At the same time, the laser beam 8 emitted from the laser oscillator 5 is also scanned by the scanning optical system 10 in synchronization with the movement of the X-Y table 12 using a command signal from the numerical control device 14 . When the wafer 3 reaches a predetermined position in this way, the pulse generator 7 oscillates a pulse signal at a predetermined frequency in response to a command signal from the numerical control device 14. The driver 6 is driven by this pulse signal, and the laser oscillator 5 emits cavity-damped pulsed laser light 8 . This laser beam 8 is focused and irradiated onto the resist 4 on the wafer 3 by a condensing optical system 11, melting and evaporating the portion of the resist 4 that has been irradiated with the laser beam, and causing the edge of the resist 4 to be affected by surface tension. Twist and excite;
As shown in FIG. 2, a portion of the resist 4 is removed so that the silicon dioxide 2 is exposed. Next, the numerical control device 14, in which the data of the specified circuit pattern shape is stored, processes this stored data according to the given program, and uses the processed result, that is, the laser oscillator according to the command. 5, the laser oscillation, the movement of the X-Y table, and the scanning of the laser beam by the scanning optical system 10 are each controlled in parallel,
A designated circuit pattern is formed on the resist 4 on the wafer 3. On the other hand, when an Ar ion laser oscillator is used as the laser oscillator 5 and continuously oscillates, the driver 6
A modulator 9 is used instead of the pulse generator 7, and the continuous wave laser beam 8 is turned on and off by the command signal from the numerical control device 14 by the modulator 9.
A circuit pattern is formed on the resist in the same manner as in the previous embodiment.

Further, circuit pattern formation in IC fabrication according to another embodiment is performed as follows.

That is, in the case of ICs, several tens to hundreds of fine identical patterns are lined up on one wafer. This one fine pattern mask reticle is placed between the scanning optical system 10 and the condensing optical system 11, and the laser beam 8 is focused on the resist through the reticle to simultaneously form one fine pattern. Next, by moving the X-Y table 12 at intervals at which fine patterns are sequentially arranged and irradiating the laser beam 8, a pattern in which several tens to hundreds of fine patterns are arranged is formed on the wafer. .

As explained above, the present invention has the following effects compared to resist pattern formation by conventional photoetching.

1) Since the present invention is a dry process that does not require processes such as exposure and development, there is no possibility of pollution caused by developing solutions (mainly organic solvents) as in the past. Since a circuit pattern is formed, the entire process can be streamlined and design changes can be made easily and quickly.

3) Since the present invention can be applied to a resist coated with a non-photosensitive resist, commonly available resists can also be used.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the resist applied to the wafer.
FIG. 2 is a cross-sectional view of the resist with a portion removed, and FIG. 3 is a schematic diagram showing an apparatus for forming a circuit pattern of the present invention, that is, a laser processing apparatus. 1: silicon substrate, 2: silicon oxide, 3: wafer...
, 4: resist, 5: laser oscillator, 6: driver, 7
Repulse generator, 8: Laser beam, 9: Modulator, 10: Scanning optical system, 12: Condensing optical system, 12: XY
Table, 13: Motor, 14: Numerical control device.

Claims (1)

[Claims] 1. A laser focused directly on a resist film attached to a substrate surface and having at least one material selected from polyisoprene, polystyrene, polyvinyl chloride, polyethylene, phenol, vinyl chloride, polyester, nylon, etc. A circuit pattern characterized by irradiating light in a predetermined pattern through a reticle, evaporating and removing the portion of the resist film irradiated with the laser light, and exposing the substrate surface to the resist film to form a circuit pattern. Formation method.