JPH03206617A - Cleaning equipment - Google Patents

Abstract

PURPOSE:To enable removal of unnecessary substances at low temperature and clean semiconductor devices without giving electrical damages by mixing coolant with ice particles as cleaning liquid. CONSTITUTION:Coolant is supplied from coolant supply tube 12. Ice particles 7 made of pure water 8 steamed by a heater 9 of an ice maker 6 are mixed with the coolant in a cleaning tub 1 equipped with an ultrasonic oscillator 2 to clean wafers. This enables removal of unnecessary substances at low temperature and cleaning semiconductor devices without giving electrical damages, and reliable semiconductor devices can be made.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultrasonic cleaning device, and particularly to a cleaning device suitable for cleaning at room temperature or below.

[Conventional technology]

FIG. 2 shows a semiconductor device, and is a diagram showing a cross-sectional structure of a main part after development processing in a photolithography process in the manufacturing process thereof. In the figure, a4 is a semiconductor substrate (hereinafter referred to as the substrate) made of silicon single crystal, etc. (141 is this substrate (1)
The resist 05 formed above is a scum made of unnecessary organic matter remaining on the substrate α1.

In such a semiconductor device, the scum Q5 becomes an obstacle that causes pattern defects and the like when performing subsequent processing such as vapor deposition and ethoching, so it is necessary to completely remove it.

Conventionally, a plasma ashing device has been used to remove this. FIG. 3 is a sectional view showing the general configuration of a conventional plasma ashing device used for removing unnecessary materials such as scum. In the figure, (4) is the wafer that will be the substrate to be processed, (5) is the wafer support stand that supports this wafer (4) in parallel, and α is the vacuum that accommodates the wafer (4) and performs the processing. Tank A is a high-frequency power source that applies a predetermined voltage to electrodes disposed above and below inside the vacuum tower Q5, electrodes α of the Cl old shell.

In the plasma anosing apparatus constructed in this way, after the wafer (4) is housed in the vacuum chamber (11), the gas in the vacuum chamber (11MQtV) is evacuated and evacuated as shown by the arrow on the right side of the figure, and then the vacuum chamber (11) is evacuated. , As shown by the arrow on the prisoner side, oxygen gas, nitrogen gas, etc. are introduced to inside the vacuum tower 019.
It causes a state of coma to the extent of r. Next, plasma is generated by applying a voltage between the electrodes 07) from the high frequency power supply a. By processing the wafer (4) in this plasma, the reactive species are removed by reacting with the scum Q5. Here, the scum Q5 has a pattern shape,
Since it causes pattern defects, it must be completely removed, and the underlying layer in that area must be treated to a state where it is completely exposed.

[Problem to be solved by the invention]

In conventional plasma anodizing equipment, scum is removed by processing in plasma, so due to its characteristics,
You will be adversely affected. That is, in the manufacturing process of semiconductor devices, in order to bring the electrical characteristics of the peninsula device into the desired normal state, processing at low temperatures and processing that reduces electrical effects are required. However, in the plasma anodizing device 1, the wafer (4) becomes high temperature due to processing in the plasma, and the exposed parts are damaged due to collisions with charged particles of the plasma, which adversely affects the electrical characteristics. However, there was a problem in that reliability deteriorated.

This invention was made to solve the above-mentioned problems, and by colliding with ice grains, unnecessary substances can be removed, processing can be performed at low temperatures, and electrical characteristics are maintained normally, making it suitable for use. An object of the present invention is to obtain a cleaning device that can perform thorough cleaning.

[Means to solve the problem]

A cleaning apparatus according to the present invention includes a cleaning tank that accommodates a substrate to be processed, an ice particle generation unit that is connected to the cleaning tower, generates ice particles of a predetermined particle size, and introduces the ice particles into the cleaning tower; The apparatus is equipped with a cooling liquid that is to be treated during the cleaning process, introduced into the cleaning tower, and mixed with the ice particles, and an ultrasonic generator provided in the cleaning tank.

[Effect]

According to this invention, when ultrasonic cleaning is performed in a cleaning liquid consisting of ice particles and a refrigerant liquid, the ice particles collide with the substrate. The energy of this collision causes the sample temperature to rise, but this rise can be prevented by the refrigerant liquid. Furthermore, since the colliding object is ice particles, electrical damage is suppressed. Moreover, the cleaning process is performed to a desired state.

[Embodiments of the invention]

FIG. 1 is a sectional view showing a schematic configuration of a cleaning device according to an embodiment of the present invention. In the figure, (4) and (5) are equivalent to the conventional one. The mountain is the cleaning tank that accommodates and processes the substrate to be processed, (2) is the bottom of this cleaning tower (the ultrasonic oscillator installed here), and (3) is the cleaning liquid introduced into the cleaning tank (1). (6) is an ice maker for the ice cleaning equipment installed on one side of the washing tower (1), (7) is an ice maker that is generated by this ice maker (6) and introduced into the washing tower (1). (8) is pure water for making ice grains (7); (9) is a heater installed at the bottom of the ice maker (6); (10 is a heater installed at the top of the ice maker (6)). αυ is a refrigerant liquid supply pipe provided on the other side of the cleaning tank (1), and Cl4 is the refrigerant liquid to be introduced into the cleaning tank (1).

In the cleaning device constructed in this way, first, on the ice maker (6) side, the pure water (8 ml) in the ice maker (6) is heated and evaporated by the heater (9), and the water vapor is evaporated by the cooler αq. It is rapidly cooled to produce ice particles (7) of a predetermined particle size.The ice particles (7) are introduced into the cleaning right (1).On the other hand, on the refrigerant liquid supply &Qυ side, is liquid nitrogen,
A refrigerant liquid 0 made of Fluorinert or the like is introduced into the cleaning tank (1). These are introduced into a cleaning tank (1), and the mixed liquid is used as a cleaning liquid (3). Next, the wafer (4) is set on the wafer support stand (5) and placed in the cleaning liquid (3).

After this, ultrasonic waves of several hundred g-1z are applied to the cleaning tower (1) using an ultrasonic oscillator (2) for a predetermined period of time. This ultrasonic wave causes the ice particles (7) to collide with the wafer (4). The scum α is removed by the impact force.By doing this, the process can be performed at low temperature without damaging the exposed part of the wafer (4), so there is no adverse effect on the electrical properties. Improving reliability is a must.

In the above-mentioned embodiment, the purpose is to remove the scum Q5, but the purpose may also be to remove the resist in the development process of the photo printing process in the manufacturing process of the semiconductor device.

Further, by using ice particles (7) having a particle size of 0.1 μm to several tens of μm, it can be applied to wafer cleaning and mask cleaning in the manufacturing process of semiconductor devices.

Furthermore, by using ice particles (7) with a particle size of several tens of micrometers or more, it can be used to remove flanox from solder used in printed circuit boards, and because it can be cleaned regardless of its shape, it can also be applied to cleaning complex-shaped objects such as ceramic workpieces. can.

〔Effect of the invention〕

As described above, according to the present invention, ice particles are mixed into the refrigerant liquid as a cleaning liquid, and unnecessary substances can be removed at low temperatures, and cleaning can be performed without causing electrical damage.
This has the effect that a highly reliable semiconductor device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cut-away diagram showing a schematic configuration of a cleaning apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the main parts of a wafer after development processing in a photolithography process in the manufacturing process of semiconductor devices.
FIG. 3 is a sectional view showing the schematic structure of a conventional plasma anosing device used for scum removal. In the figure, (1) is a cleaning tower, (2) is an ultrasonic oscillator,
(3) is cleaning liquid, (4) is wafer, (6) is ice maker, (
7) is ice grains, (8) is pure water, (9} is a heater, Oli is a cooler, αυ is a refrigerant liquid supply bowl, and α is a refrigerant liquid. Note that the same symbols in each figure are the same. , or a significant portion.

Claims (1)

[Claims] a cleaning tank for accommodating a substrate to be processed; an ice particle generation unit connected to the cleaning tank to generate ice particles of a predetermined particle size and introducing them into the cleaning tank; a cooling liquid to be introduced into a cleaning tank and mixed with the ice particles;
A cleaning device comprising an ultrasonic generator provided in the cleaning tank.