JPS60189926A - Method and device for forming vapor phase thin film - Google Patents

Abstract

PURPOSE:To enable rapid formation of a multilayer film by a metod wherein, using a sample-substrate rotation means arranged so as to be part of a partition, the sample substrate is rotated by the rotation of a rotary shaft parallel to the substrate surface, so as to successively contact a plurality of raw material gasses. CONSTITUTION:A gas bath 21 is partitioned by the partition 22, and two reaction chambers 23 and 24 independent of each other are formed. A sample-substrate holding device 25 rotates by the rotation of the shaft parallel to the substrate surface of the sample substrate 26, and exposes the substrate surface to the inside of the chambers 23 and 24 alternately. For example, a tungsten film is formed by photo dissociation of tungsten carbonyl in the chamber 23 by using a KrF excimer laser 27 of 248nm wavelength. The mixed gas of ammonia and silane is underwent to photochemical reaction by irradiation of the chamber 24 with a laser beam of 193nm wavelength from an ArF excimer laser 30, resulting in the deposition of an Si nitride film by adhesion on the sample substrate 26. In such a manner, desired multilayer wirings are formed by alternately laminating metallic films are dielectric films.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention uses radiation such as ultraviolet rays and infrared rays to dissociate a compound gas and deposit a desired substance on a sample substrate to form a thin film. The present invention relates to a vapor phase thin film forming method and an apparatus for implementing this method.

(Prior art and their melting points) In recent years, with the rapid development of semiconductor devices, coatings of metals, semiconductors, dielectrics, etc. The technology to form chromatography on sample substrates has become very important. In particular, the laser vapor phase thin film formation method, in which a source gas containing a compound gas is irradiated with laser light, the compound gas is dissociated by K, and a desired substance is deposited on a sample substrate to form a thin film is a patterning method. Easy to irradiate;
Recently, many attempts have been made due to the possibility of lowering the process temperature.

For example, Applied, Physics, Letters (App +
1edAhysics Leuers) Conclusion Volume 41 19
In the paper published in the December 1, 1982 issue, pages 1048 to 1050 entitled "Low-temperature deposition of high-melting point metal thin films" [2], as shown in Figure 1, compound gas 1
A sample substrate fixing type in which a high melting point metal thin film is formed on the sample substrate 3 by causing the sample substrate 3 to flow into a gas tank 2 and irradiating the sample substrate 3 with ultraviolet laser light 5 through a lens optical system 4. Helium gas is blown as a purge gas into a window 6 provided in a gas tank 2, which shows the structure of the vapor phase thin film forming apparatus, to prevent fogging. In this example, carbonyl compounds such as Mo, W, and Or are used as the compound gas.

However, such a conventional vapor phase thin film forming apparatus having a sample substrate fixed structure has serious drawbacks as described below.

In other words, in order to form a multilayered film with different compositions, it takes a long time to evacuate the old raw material gas from multiple sources, finish it, and then introduce new raw material gas into the gas tank to stabilize the gas pressure. Since it requires many hours of waiting time, the work efficiency is low and it is uneconomical. In addition, if you try to treat multiple different raw material gases using the same exhaust treatment system, it will be difficult to take thorough measures against pollution, and you will also have to install very expensive exhaust treatment equipment. It is also uneconomical.

(Objective of the Invention) An object of the present invention is to provide an economical method for forming a vapor phase thin film, which can rapidly form multilayer coatings having different compositions, and an apparatus for carrying out the method.

(Structure of the Invention) The method for forming a vapor phase thin film according to the present invention includes a step of supplying a plurality of raw material gases containing different compound gases while spatially separating each other, sequentially exposing a sample substrate to the plurality of raw material gases, and sequentially exposing a sample substrate to the plurality of raw material gases. , the source gas to which the sample substrate is exposed is irradiated with energy rays to dissociate the source gas, and the desired substance generated by this dissociation is deposited at a desired location on the surface of the sample substrate.
The structure includes a step of attaching and dying VC.

The structure of the vapor phase thin film forming apparatus according to the present invention includes a gas tank having a partition wall inside so that a plurality of raw material gases containing different compound gases flow separately from each other, and a gas tank having a partition wall inside to separate and flow the different compound gases. Energy IIj for each dissociation! irradiation means, and the sample substrate is rotated around an axis parallel to the sample substrate surface so that the sample substrate surface can sequentially come into contact with the plurality of raw material gases flowing separately from each other. The present invention is characterized in that the sample substrate rotating means is provided as a part of the partition wall.

(Operation/Principle of the Present Invention) The principle of the vapor phase thin film forming method according to the present invention is that a partition wall is provided in a gas tank so that a plurality of raw material gases containing different compound gases are separated from each other and flow. The sample substrate is rotated by rotation of a rotation axis parallel to the substrate surface using a sample substrate rotation means arranged so that the substrate surface of the sample substrate is separated from the plurality of source gases flowing from each other. By sequentially contacting the substrate, a multilayer coating can be quickly formed on the surface of the substrate.

(Example) Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, a gas tank 21 is partitioned by a partition wall 22 into two mutually independent reaction chambers 23.
24 is formed. The reaction chamber 23 contains tungsten carbonyl (W(Co)a) diluted with argon gas.
Gas is supplied.

The dilution ratio in this example was 4:1, and the total pressure was 8 Torr.
It is. The sample substrate holding device 25 can rotate around an axis parallel to the substrate surface of the sample substrate 26, and holds the substrate surface between the reaction chambers 23 and 24 without substantially impairing the airtightness between the reaction chambers 23 and 24. can be exposed alternately. The reaction chamber 24 contains ammonia (NH,) and silane (SiH).
, ) is supplied. The flow rate ratio of ammonia and silane is 1o:1, and the total pressure of the mixed gas is 8To.
It is rr. Tungsten carbonyl k wavelength 248
When photodissociation was performed using a KrF excimer laser 27 with a wavelength of 0.1 nm, a 0.1
A tungsten film for wiring could be formed at a film formation rate of 7 μm/min. A photomask 28 and an imaging optical system 29 were installed on the optical path of the laser beam, so that a desired wiring pattern could be formed on the sample substrate 26. The sheet resistance was approximately 5Ω when the thickness of the tungsten film was 0.3μm.

In addition, when the reaction chamber 24 was irradiated with laser light with a wavelength of 193 nm from an A'rF excimer laser at 3° to cause a photochemical reaction in the mixed gas of ammonia and silane, the film formation rate was approximately 0.5 μm/min. A silicon nitride film could be deposited on the sample substrate by pressure deposition. When the obtained silicon nitride film was evaluated, it was found that a good dielectric film with low leakage current and surface charge density and high withstand voltage was obtained, and the film quality was much better than that of the silicon nitride film obtained by ordinary plasma CVD method. It turned out to be excellent. In this case as well, by installing the second photomask 3 and the second imaging optical system 32 on the optical path of the laser beam, it was possible to form a dielectric film having a desired insulating film pattern.

The sample substrate 26 is successively rotated by the sample substrate holding device 25, and the substrate surface is alternately exposed to the reaction chambers 23 and 24 to alternately laminate the gold coating and the dielectric coating, thereby forming the desired multilayer wiring. was able to form.

The reaction product produced by the optical vapor phase deposition reaction is exposed to the window 33.
．． 34, the transmittance of the window decreases and it becomes difficult to form a high-quality thin film on the sample substrate with good reproducibility. In both cases, argon gas is blown as a purge gas.

Although a silicon wafer was used as the sample substrate 26 in this example, a good film could be formed even when a quartz glass substrate or a ceramic substrate was used instead. In this decoration example, we have explained the use of multilayer metal films and dielectric films as an example to form multilayer wiring.
Of course, it is also possible to form the HA of a semiconductor such as aAs.

It is also possible to incorporate a heater into the sample substrate holding device 25 used in this example, and thereby the film quality of the film can be controlled more precisely.

FIG. 3 is a schematic diagram showing a schematic cross-sectional structure taken along line 1-A in FIG. 2. In the figure, a damper 35 with appropriate spring elasticity is attached to the partition wall 22 and lightly presses the side surface of the sample substrate holding device 25), thereby maintaining airtightness between the reaction chambers 23 and 24 separated by the partition wall 22. It's starting to drip.

FIG. 4 is a schematic diagram showing a schematic cross-sectional structure of a sample substrate rotating means section according to a second embodiment of the present invention.

In the figure, the covers 36 and 37 are attached to the sample substrate holding device 25.
The cover is designed to open and close in synchronization with the 0 rotation.The cover located on the back side of the sample substrate 26 is normally closed.
By evacuating the space between the closed cover and the substrate holding device 25 under reduced pressure, mixing of source gases between different reaction chambers can be almost completely prevented.

Regarding the embodiment of the present invention, the case where the number of reaction chambers is two has been described, but the number of reaction chambers can be further increased by arranging a plurality of partition walls radially around the rotation axis of the sample substrate holding device 25. It is also possible to increase the number of raw material gases used simultaneously. Further, in the above embodiments, an excimer laser was used as a radiation source for dissociating compound gases, but the present invention is not limited to this, and it is of course possible to use other laser light sources, lamp light sources, etc.

(Effects of the Invention) When a multilayer wiring film was formed using the vapor phase thin film forming apparatus shown in the first embodiment of the present invention, it was found that when a conventional vapor phase thin film forming apparatus with a fixed sample substrate structure was used, In comparison, the working time required to form a thin film was significantly shortened to 1/10 or less, which greatly contributed to improving production efficiency. Furthermore, by using the vapor phase thin film forming method and apparatus according to the present invention, it is possible to individually install an optimal and low-cost exhaust gas treatment system for each of a plurality of source gases. Overall equipment costs were much lower. As described in detail above, according to the present invention, there is provided an economical method for forming a vapor-phase thin film and an apparatus for carrying out the method, which can quickly form multilayer coatings having different compositions.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a conventional vapor phase thin film forming apparatus, FIG. 2 is a block diagram diagram showing the configuration of an embodiment of the present invention, and FIG. 3 is a schematic cross-sectional structure of the section A-A in FIG. 2. FIG. 4 is a schematic diagram showing a schematic cross-sectional structure of a sample substrate rotating means section according to a second embodiment of the present invention. In the figure, 1... Compound gas, 2... Gas tank, 3
... Sample substrate, 4... Lens optical system, 5... Ultraviolet laser light, 6... Window, 21... Gas tank, 22...
Partition wall, 23.24...Reaction chamber, 25...Sample substrate medical holding device, 26...Sample substrate, 27...KrF excimer laser, 28...Photomask, 29...Imaging optical system , 30... ArF excimer laser, 31... second photomask, 32... second imaging optical system, 33.
34...Window, 35...Damper, 36.37...Cover. 71 Figure

Claims (2)

[Claims] (1) A step of supplying a plurality of raw material gases containing mutually different compound gases in a manner that is spatially isolated from each other, and sequentially exposing a sample substrate to the plurality of raw material gases. A step of irradiating the source gas to which the sample substrate is exposed with energy rays to dissociate the source gas, and depositing a desired substance produced by this dissociation at a desired position on the surface of the sample substrate! A method for forming a vapor phase thin film, comprising: (2) A gas tank having partition walls inside so that a plurality of raw material gases containing different compound gases flow separately bVc from each other, and energy ray irradiation for dissociating the different compound gases by irradiating them with energy rays. and pressure such that the sample substrate can be rotated around an axis parallel to the sample substrate surface so that the sample substrate surface can sequentially contact the plurality of raw material gases flowing separately from each other. A vapor phase thin film forming apparatus characterized in that the sample substrate rotating means is pressed so as to become a part of the partition wall. Review