JPS63128722A - Photo processing method - Google Patents

Abstract

PURPOSE:To prevent deterioration for a long-term use and to make intensity of ultraviolet rays be adjustable, by generating ultraviolet rays in a plasma generating chamber by the use of interaction between magnetic fields and an electric field and introducing the ultraviolet rays into a reaction space which is linked with the plasma generating chamber and performing photo processing of a processing surface. CONSTITUTION:A plasma generating chamber 2, where interaction between magnetic fields 5, 5' and an electric field is used to generate ultraviolet rays, is disposed on an upper part of a container 1'. Wavelengths of ultraviolet rays can be controlled by replacing gases introduced into the ultraviolet-ray generating device 2. An electric field energy is supplied to this space for ultraviolet-ray generation through a microwave power source 3, a tuning device 4, and a quartz window 18. A bubbling operation of a mercury bubbler 11 is performed by argon from a doping system 13, and mercury vapor and argon gas are also introduced from this system in order to generate the ultraviolet rays. The ultraviolet rays are generated in the ultraviolet-ray generating space 2 by the use of ECR plasma, and photo etching is performed on a processing surface of a substrate disposed in a reaction space 1 by the use of them.

Description

Detailed Description of the Invention Field of Application of the Invention 1 The present invention provides an optical treatment method in which ultraviolet light is generated using the interaction of an electric field and a magnetic field, and the ultraviolet light is used to perform optical treatment on a surface to be treated. Regarding. The present invention performs phototreatment such as photoetching of a phototreated surface, ultraviolet cleaning using photochemical reaction (also referred to as UV cleaning or photocleaning because ultraviolet light is used), and photovapor phase reaction. Furthermore, the present invention aims to automate and simplify the process of semiconductor integrated circuits (hereinafter referred to as LSI).

rPrior Art J As a gas phase reaction treatment method using ultraviolet light, a photoetching method or a photoCVD method is known, which is carried out by activating a reactive gas with light energy.

As a method of generating ultraviolet light, an ultraviolet light generating device using only a low-pressure mercury lamp or microwave is known. However, in all of these methods, the intensity of the ultraviolet light generated was insufficient.

Furthermore, an excimer laser that generates intense ultraviolet light in a pulsed manner is known.

``Problems with the prior art j'' Performing these light treatments using continuous light is extremely important in the optical CVD (chemical film deposition) method. However, when using a low-pressure mercury lamp as the ultraviolet light source as a means to obtain this continuous light, However, the emission intensity was insufficient, resulting in a low light processing speed, which was a problem.Therefore, a means to generate strong ultraviolet light was needed.

Furthermore, the excimer laser, which is known as a strong ultraviolet light source, emits discontinuous light and has an extremely small irradiation area of 2 to 4 cm. Therefore, it can only be used in special industrial applications, and the large area required by the present invention It cannot be used as a means to obtain continuous light.

Means to Solve the r Problem J The present invention is a light processing method using a light generating device that generates ultraviolet light using the interaction of a magnetic field and an electric field in order to meet such demands.

Using this device, ultraviolet light cleaning (Uv cleaning using ultraviolet light), UV etching, or photoCVD (vapor phase film formation) is performed using ultraviolet light generated using the interaction of the magnetic field and electric field of the present invention. ) etc., it becomes possible to carry out ultraviolet light treatment in the same reaction device, which is possible only with large area and continuous light.

Furthermore, in the present invention, the interaction of a magnetic field and an electric field,
In particular, electron cyclotron resonance (also referred to as ECR) conditions are used to generate ultraviolet light, and this resonance region is used to generate a strong ultraviolet light source. Therefore, for the generation of ultraviolet light under BCR conditions, one or more of argon, deuterium, krypton or mercury is introduced into this plasma space;
The resonance emission of these gases is used to generate strong ultraviolet light.

As a result, it has a large area of 20 cm in diameter and a diameter of 185 nm.
It has become possible to generate ultraviolet light with a wavelength of 10 mW/cm2 or more at a strong illuminance of 10 mW/cm2 or more.

``Effect'' Then, due to the strong light of the ultraviolet light source that uses this electromagnetic energy, the natural light that has been formed on the surface to be formed is removed.
Oxide can be photolyzed and removed, and hydrocarbons caused by backflow of oil vapor from the vacuum pump can also be photolyzed and gasified to prevent adsorption to the surface to be treated. In addition, during this ultraviolet light cleaning, if the surface of the substrate to be formed is made of a material that particularly dislikes oxygen, for example an m-v compound such as GaAs, a reactive gas for cleaning such as ammonia or hydrogen may be added to the reducing atmosphere gas. Place this material. These gases are then irradiated with strong ultraviolet light to excite them and remove dirt from the surface. Furthermore, if the surface to be processed is an organic material such as photoresist, by introducing oxygen and activating or decomposing it with ultraviolet light and bringing it into contact with the processing surface, dirt and unnecessary materials on the surface can be etched ( ashing).

In the present invention, the excited state of the excited reactive gas can be maintained by emitting 185no+ light (with an intensity of preferably 10 mW/cm" or more) having the resonance emission wavelength of mercury using ECR conditions as an ultraviolet light source. .

A window that is transparent to ultraviolet light is provided between a space where ultraviolet light is generated and a reaction space where a substrate having a processing surface is disposed. This window was used to shield the gas from mixing with the gas used for cleaning.

As a result, even if mercury, deuterium, etc. are present in the generation space, any type of gas atmosphere or any pressure can be provided in the processing space.

Further, by heating the substrate at a temperature of room temperature to 500° C., etching of unnecessary materials on the surface of the substrate to be formed can be promoted.

The present invention will be illustrated below with reference to Examples.

Embodiment 11 FIG. 1 shows an outline of a magnetic field microwave excitation type ultraviolet light generating light source of the present invention and a processing type device using the same.

In the drawing, there is a reaction space (
1) is configured. This container has an outlet (1'') for taking out the substrate (10), the substrate (10) is placed in a substrate holder (10') at the bottom, and a halogen lamp heater (7) is installed on the back side to heat the container. On the other hand, at the top of the container (1) is a magnetic field (5) that generates an ultraviolet light source.

(5゛) and plasma generation chamber (2) using electric field interaction (plasma generation space for generating ultraviolet light,
In other words, it has an ultraviolet light generation space). This ultraviolet light generator (
2) The wavelength of the ultraviolet light is controlled by changing the gas introduced. In this ultraviolet light generation space, a microwave power source (3),
Electric field energy is supplied through the tuning device (4) and the quartz window (18). When generating ultraviolet light, the mercury bubbler (11) is bubbled with argon from the doping system (13), and mercury vapor and argon gas are introduced, for example, from (24) to generate ultraviolet light. Furthermore, a reactive gas for etching or ashing was introduced from the doping system (13) through (26), argon was introduced through (25), and the reactive gas was activated by ultraviolet light (2 days). Good too. The window (19) is transparent to ultraviolet light.

In this way, ultraviolet light is generated in the ultraviolet light generation space (2) using ECR plasma, and these are used to generate ultraviolet light in the reaction space (2).
It became possible to perform photoetching on the processing surface of the substrate arranged in 1).

Experimental Example 1j This experimental example is an application example in which the apparatus of Example 1 was used to perform ultraviolet light cleaning of the photo-etched surface of a silicon semiconductor.

A substrate in which silicon oxide was formed on a silicon semiconductor and a photoresist was formed thereon was used.

Using this photoresist as a mask, ECR of silicon oxide
Anisotropic etching was performed using plasma, and silicon oxide could be anisotropically etched at an etching rate of 2,500 people/min. That is, the microwave in Figure 1 is (3
) at a frequency of 2.45 GHz and an output of 30 to 500, for example 200. Magnet (5), (5'
) was set to have a resonant magnetic field strength of 875 Gauss. The pressure in the ultraviolet light generation space (2) was 0.002 torr, and argon was supplied as a non-product gas from (25) at a rate of 50 cc/min.

Then, mercury and argon were added to the ultraviolet light generation space (2) from (24) to generate strong ultraviolet light of 185 nm. Unnecessary argon was exhausted from valves (14') and (15').

At this time, the pressure in the reaction chamber (1) is set at 10 to 100 torr, and the organic matter (2
7).

In this way, contaminants such as hydrocarbons on the silicon semiconductor could be removed.

The object to be etched is not only silicon oxide, but also silicon nitride, silicon semiconductors, metal silicides, alloys, and other electronics application equipment, such as all that require the manufacturing process of semiconductor integrated circuits. It can be implemented by

"Experimental Example 2" In this experimental example, a silicon nitride film was formed on a substrate by a photovapor phase reaction method.

As in Experimental Example 1, 875 Gauss was created using the magnets (5) and (5''').With the doping system (26),
Disilane (SigL) or trisilane (Si!Hs)
and ammonia (NH3) were introduced. NH3/(S
i2H4 or 5iJa) = 10, and the reaction pressure was 1
The temperature was 0 torr and the substrate temperature was 300°C. Silicon nitride was then obtained at film growth rates of 30 and 50 people/min. As a result, compared to the previous direct excitation method using a low-pressure mercury lamp, which required 10 to 15 people and 7 minutes, the
The growth rate was sufficient to enable practical use four times as high. Furthermore, the maximum film thickness of the coating is 1800 and 2400, respectively.
I was able to get people. Considering that conventional low-pressure mercury lamps could only be used for up to 1,000 people, it can be effectively used as an anti-reflection coating for compound semiconductors such as 1nP.

This formed film is made of silicon oxide and trimethylaluminum (T) by the reaction between silane (SiH4) and oxygen (02).
! 'IA) and oxygen (02) to form alumina. Furthermore, it is also possible to form a silicon semiconductor using disilane or trisilane. Furthermore, metal may be formed.

``Effect 1 As is clear from the above explanation, the present invention uses microwaves and a magnetic field as an ultraviolet light source.

Since the present invention does not use a mercury lamp unlike conventional light processing devices, the ultraviolet light source does not deteriorate due to long-term use, and the intensity of the ultraviolet light can also be adjusted by changing the intensity of the magnetic field.

Furthermore, in the present invention, dirt that has adhered or formed in advance, or dirt that is newly adsorbed immediately after film formation or in the reactor, is removed by ultraviolet light cleaning.

In FIG. 1 of the present invention, etching or film formation treatment was performed on the upper surface side of the substrate. However, if this drawing is turned upside down,
It goes without saying that the substrate may be placed on the bottom or on the side (in the vertical direction), and the light source and the resonator may be placed on the top or on the side.

In addition, in the present invention, when the reaction space and the ultraviolet light generation space have the same pressure, and the gas used for the ultraviolet light generation means is not expensive or toxic, or when the ultraviolet light generation gas is brought into the reaction space by binning of the magnetic field. If release is difficult, the window (Fig. 1 (19)) may be removed.

[Brief explanation of the drawing]

FIG. 1 shows ultraviolet light treatment using a magnetic field according to the present invention. 1...Reaction space 4...Tuning device 5.5°...Magnet 9...exhaust pump 10, 10'... Board, board holder 11...Mercury bubbler 13...Doping system 14.15...Valve 14″, 15°・Valve

Claims (1)

[Scope of Claims] 1. A plasma generation chamber maintained in a reduced pressure state, a magnetic field generation means provided surrounding the generation chamber, a means for supplying microwaves to the plasma generation chamber, and a means for supplying ultraviolet light to the plasma generation chamber. having means for introducing a gas to generate
Ultraviolet light is generated in a plasma generation chamber using the interaction of a magnetic field and an electric field, and the ultraviolet light is led to a reaction space connected to the plasma generation chamber to optically treat the surface to be treated. A light processing method characterized by: 2. The optical processing method according to claim 1, wherein the optical processing comprises optical cleaning or optical ashing. 3. The optical processing method according to claim 1, wherein the optical processing comprises forming a film on the surface.