JPS6074534A - Method and equipment for forming thin film - Google Patents

Abstract

PURPOSE:To form a thin film having a flat surface on a substrate by a method wherein a device for deposition of a thin film and an etching device are independently provided, and these devices are used simultaneously or alternately. CONSTITUTION:When an SiO2 film is going to be formed on a substrate 6, the interior of a vacuum chamber 5 is evacuated using an exhaust hole 4, and the air pressure of said vacuum chamber is brought to approximately 10<-4>-10<-5>Pa. Then, a microwave power is applied to a microwave ion source 7, SiH4 and O2 are introduced from gas introducing holes 2 and 3, sais SiH4 and O2 are made to react each other by generating microwave discharge, and an SiO2 film is deposited on the substrate 6 using a CVD method. On the other hand, Ar is introduced from a gas introducing hole 1, Ar ions are generated by applying electric power on a hot filament type ion source 8, the Ar ion beams accelerated by a grid 13 are made to irradiate on the substrate 6, and the surface of the SiO2 film deposited on the substrate 6 is flattened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a thin film forming method and a thin film forming apparatus, and more specifically, a thin film forming method and a thin film forming apparatus particularly suitable for forming an insulating film such as an Smu02 film. Regarding.

[Background of the invention]

The bias sputtering method, in which sputtering is performed while applying a bias voltage to the object to be processed, has the advantage that it can simultaneously deposit a film of, for example, SiO, and flatten the surface of the film.

The bias sputtering method is a method in which a part of the deposited 5fOz etc. is simultaneously etched while depositing SiO2 etc. to form a film of 5IO2 etc. The film surface is flattened during film formation. This occurs because the rate of etching depends on the shape of the underlying material.

In other words, in the bias sputtering method, the etching rate on the sloped part of the base is higher than the etching rate on the flat part, so the protrusions on the surface of the deposited film caused by the protrusions on the base become smaller as etching progresses. Finally, surface flattening is achieved.

In the bias sputtering method, in order to sufficiently flatten the film surface, it is necessary to increase the etching rate during film formation to a re-sputtering rate of 30 to 80 inches. It is necessary to set the high frequency power applied to the substrate on which the target power is to be 15 to 40 inches higher than the target power.

As a result, the substrate is directly exposed to glow discharge and S! There is a problem in that the temperature rises not only due to the condensation energy of 0.02 and the collision energy of incident charged particles, but also due to radiation from the glow discharge.

Moreover, insulating films such as SiO□ have a lower sputtering rate than metal films, so in order to obtain a sufficient formation rate,
Even greater high-frequency power must be applied to the target, and the substrate temperature also increases due to radiation from the target.

Furthermore, since the film is formed by sputtering, there is a problem that the film deposition rate is slow, and a solution has been desired.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thin film forming method and a thin film forming apparatus that can solve the above-mentioned conventional problems and form a film with a flat surface without greatly affecting the substrate.

[Summary of the invention]

In order to achieve the above object, the present invention forms a thin film with a flat surface on a substrate by using independent means for depositing a thin film and means for etching, and using both simultaneously or alternately. .

In the present invention, if the plasma and glow discharge generated from the thin film depositing means and the etching means are localized in the vicinity of the means, the influence of the plasma and glow discharge on the substrate can be reduced, and The rise in temperature can be reduced.

Furthermore, if the plasma or glow discharge is not localized, the temperature rise of the substrate cannot be suppressed, but there is an advantage that the film deposition rate is extremely high.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to Examples.

Embodiment 1 FIG. 1 is a diagram for explaining an embodiment of the present invention.

A vacuum chamber 5 serving as a reaction vessel is equipped with a gas inlet 1.2° 3 and an exhaust port 4, and is further provided with a microwave ion source 7 for depositing a film on a substrate 6 and for etching the surface of the substrate 60. Each of the hot filament ion sources 8 has an independent hot filament type ion source 8 for the purpose. Note that the substrate 6 is held on a rotatable susceptor 9 by quartz 12.

To explain the case of forming a 5LOZ film on the substrate 6 as an example, first, the inside of the vacuum chamber 5 is evacuated through the exhaust port 4,
The internal air pressure is approximately 101 to 1 O-5 pa.

Next, the microwave ion source 7 is supplied with a frequency of 2, . 45
GHZ microwave power is applied, and monosilane (SiH4) and oxygen (02
) and generates microwave discharge to
By reacting H4 and 02, CvD (Chemical V
An 810z film was deposited on the substrate 6 by apor deposition.

On the other hand, argon (At) is introduced from the gas inlet 1, power is applied to the hot filament ion source 8 to generate Ar ions, and the resulting Ar ion beam is accelerated by the grid 13. The substrate 6 was irradiated to etch the 810 g film deposited on the substrate 6 to flatten the surface.

Note that the substrate 6 includes a susceptor 7/9 whose interior is water-cooled.
was adsorbed by an electrostatic chuck and rotated together with the susceptor 9.

In this way, the impact of charged particles from the microwave ion source 8 on the substrate 6 is prevented by the grid 14, and as a result, the temperature rise of the substrate 6 is significantly suppressed.

That is, FIG. 2 is a curve diagram showing the relationship between the formation rate of a 5iHz film and the substrate temperature, and curves a and b show the results obtained by the conventional bias sputtering method and the present invention, respectively.

Here, the above curve shows that the pressure inside the vacuum chamber 5 is 6.7
10-" pa, the gap between the center of the substrate 6 and the microwave ion source 7 and hot filament type ion source 8,
The results are shown when the etching amount was 15 crn and the ratio of the etching amount to the thin film deposition amount during film formation was 30 crn.

As is clear from FIG. 2, the 5fOz film according to the present invention! When forming the substrate, the temperature rise of the substrate is much smaller than when using the bias sputtering method. It can be seen that the amount is less than 1/2 that of the bias sputtering method.

Also, assuming that the allowable increase in substrate temperature is 250C,
Even when bias sputtering is used, the formation rate of the 5fOz film is more than tripled.

This improvement in substrate temperature rise is due to the fact that the plasma source is separated from the substrate, which reduces heat radiation to the substrate.
In addition, it is thought that this is because the grid 14 suppressed the impact of charged particles on the substrate.

Example 2 FIG. 3 shows another embodiment of the invention.

Both the microwave ion source 7 and the hot filament type ion source 8 are provided on the bottom surface of the vacuum chamber 5, and a rotatable susceptor 9 is provided at a position facing both of the ion sources 7 and 8.

A plurality of f3i substrates 66' are fixed on the susceptor 9, and the microwave ion source 7 and the hot filament type ion source 8 are operated while the susceptor 9 is rotated.

In this way, when the substrates 6, 6' are located above the microwave ion source 7, the 5io2 film is deposited by CVD as in the embodiment, and reaches above the hot filament type ion source 8. Then, since the deposited SiQ and the film are etched by Ar ions, the film deposition and etching are performed alternately. As a result, each substrate 6° 6' is cooled without being exposed to heat radiation from both the ion sources 7 and 8, except when it is in a position facing the microwave ion source 7 or the pot filament type ion source 8. The suppression of the substrate temperature rise is even more remarkable in the case of the embodiment, and film deposition and surface flattening can be achieved while effectively preventing the substrate temperature rise.

The above example shows the case where an 8102 film is formed using SiH2 and 02 as raw material gases, but for example,
The present invention can also be used when forming other insulating films such as an s N4 film or a phosphorous glass film, a metal film, or an alloy film.

In the above embodiment, a microwave ion source was used as the plasma for promoting the gas phase reaction between the raw material gases, but it is also possible to use other plasma generation means.

It goes without saying that ions other than Ar ions used in the above embodiments may be used to flatten the surface of the deposited film. For example, various particle beams other than ions such as a neutral beam may be used. It is also possible to perform etching.

As a means for depositing a film on a substrate, in addition to the above-mentioned (9) CVD, sputtering can also be used, although the deposition rate is slow. In this case, if an inert gas is introduced into the microwave ion source in addition to a reactive gas such as SJ02, and quartz is placed on the side wall of the opening of the microwave ion source, StO.

Film deposition is performed.

Further, various means may be added to facilitate the implementation, such as providing an openable/closable shutter between the microwave ion source or hot filament type ion source and the substrate.

〔Effect of the invention〕

As described above, the present invention provides a means for depositing a film and a means for etching the deposited film to planarize the surface thereof, independently of each other.

Therefore, compared to the conventional bias sputtering method, the temperature rise of the substrate is much smaller, and when CVD is used as a film deposition method, the film deposition rate becomes extremely rapid.

Since the film deposition means and etching means can be controlled independently, it is easy to control the film deposition rate and surface flatness to desired values.

Furthermore, when the film deposition means has a grid, the film deposition rate is slightly lower, but the impact of charged particles is suppressed and the rise in substrate temperature is extremely small.

On the other hand, when the above-mentioned grid is used, the effect of suppressing the substrate temperature is not very large due to the impact of charged particles, but the film deposition rate becomes extremely high. can correspond to

All of these features were not possible with conventional methods, and are extremely useful for forming a film with a flat surface.

[Brief explanation of drawings]

It is a figure showing an example. 1.2.3...Gas inlet, 4...Exhaust port, 5...
・Vacuum chamber, 6.6/...Substrate, 7...Microwave ion source, 8...Hot filament type ion source, 9.
...Sasep (11) Ri, 10.11...Electromagnet, 12...Quartz, 13° (12) 1st item 2nd Figure 5 LO2 film #8 distance (Continued from 1st page 0 shots Akira Mukai - Department Kokubunji City Higashi Koigakubo Research Institute

Claims (1)

[Claims] 1. Deposition of the film on the substrate using a means for depositing a film on the substrate, and depositing the film on the substrate by means of irradiating the film with a particle beam, which is provided independently of the means for depositing the film. a step for forming a desired thin film on the substrate by simultaneously or alternately performing irradiation with particle beams; and the step provided independently of the means for depositing the film. A thin film forming apparatus comprising at least means for etching the film by irradiating the film with particles.