JP2651071B2 - Device fabrication method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to the production and use of gases, and more particularly to the fabrication of gas and electronic devices.

[0002]

2. Description of the Related Art In the production of many electronic devices and optical devices, crystal growth is performed from a gas phase precursor. For example, GaAs-based integrated circuits for specific applications have begun to be marketed and require precursors such as arsine. In addition, compound semiconductor materials such as gallium arsenide phosphide, indium gallium arsenide phosphide, indium gallium arsenide, indium arsenide, indium aluminum arsenide phosphorus, gallium aluminum arsenide, and III-V materials such as gallium arsenide antimony are arsine and phosphine. And is widely used in the manufacture of solid-state lasers, light-emitting diodes, field-effect transistors, and photodetectors.

[0003] Various vapor phase epitaxy methods such as organometallic pyrolysis (MOCVD), hydride vapor phase epitaxy (VPE), molecular beam epitaxy (MBE), and gas source MBE have been used. In these processes, a precursor gas interacts with another precursor gas by an energy source, ie, heat, plasma, or photons, to produce the desired crystal growth. Many common precursor gases, such as arsine, are highly toxic and their handling requires special consideration. (For various processes using precursors such as arsine for device fabrication, see Th
e BOCA National Fire Prevention Code / 1987 Building
Officials and Code Administrations, Int. Inc. 7th
See Ed. Country Club Hills, Ill. 60 447) Complete devices have been made, but the precursors are usually supplied at a concentration of 0.1 to 100 volume percent from a compressed gas cylinder. Due to the particularly toxic nature of the gas, bursting of gas cylinders or direct piping from such cylinders is undesirable.

[0004]

There are few methods for reducing the danger associated with storing a large amount of gas during device fabrication.
One method is to produce arsine by a catalytic reaction of copper arsenic and phosphoric acid. In this reaction, the amount of arsine produced can be controlled to be limited to the amount needed immediately for device fabrication. In these processes, arsine is produced at relatively low pressure. Typically, arsine at a pressure of 150 Torr or less is produced. Further, the post-reaction treatment of the catalyst material and the secondary product becomes a major problem. Accordingly, it is an object of the present invention to provide a method and apparatus capable of supplying a precursor gas without the need for storing a large amount of gas with a compressed gas source in fabricating a device using a gas source.

[0005]

SUMMARY OF THE INVENTION Certain high energy electron injection processes for producing hydride gases, such as arsine and phosphine, provide sufficient precursor gas in fabricating devices such as semiconductor or optical devices. Supplied on the spot. That is, in the present invention, at least one gas for device fabrication is generated by a gas synthesis process, and this gas is used directly in the fabrication process without storing a large amount of precursor gas. The chemical reaction stage by high energy electron injection is
Used as part of a device fabrication process, a gas containing hydrogen and a volatile group V or VI (eg, a material containing phosphorus, arsenic, selenium, tellurium) is introduced into a gas into which high-energy electrons are injected. . At radio frequencies or microwaves (frequency band from 13.5 MHz to 2450 MHz), the pressure in the gas-phase reactor is 0.
Sufficient gas generation cannot be performed so as to be 2 atm or more. However, due to the reaction resulting from the high energy electron injection, sufficient precursor gas is supplied for device fabrication (up to 1 atm) and used in situ.

[0006] As mentioned above, certain gas phase steps are used to produce hydrogenated gases and used in situ for device fabrication processes. Buckley et al., Applied Physiology, describes the use of a gas such as arsine or phosphine for device fabrication in various devices.
cs Letters, 57, 1684 (1990), Cox et al., Journal of Cry
stal Growth, 73, (1983), Olsen et al., "Progress in C
rystal Growth and Characterization ", Vol. 2, Ed.
BR Panplin, Pergamon Press, Oxford, 1989, JJTie
tjan et al., Journal of the Electrochemical Society,
113, (1966), and PDDapkus, Annual Review of M
aterial Science, (12), pg. 243, 1982. The remainder of the gas generation steps used in the device fabrication steps are described in detail below for an understanding of the present invention.

[0007] A mixture of reactive groups, atoms and ions is maintained in a gaseous state by injection of high energy electrons. Accelerated electrons are not the only form of energy for gasification, but such electrons must
Also, a thermally induced reaction is necessary to improve the efficiency which is insufficient. The supply of electrons can be continuous, pulsed, or periodic. Normally, high-energy electrons having an energy of 0.1 keV or more are used.
Used in the range of keV. The exact electron energy required to achieve the required reaction gas concentration (ie, 2 to 30 volume percent in the range of 10 Torr to 1 atm) depends on the type of gas being generated. For example, 10k
The energies of eV and 30 keV are used for phosphine and arsine, respectively. The electron current need not be strictly specified, but is on the order of a few milliamps. The electron source does not need to be specified, and a Tesla coil, a beta emitter, an electron gun, or the like can be used.

[0008] The hydrogen source introduced into the reactive gas is not necessarily specified, and may be any of atoms and molecules. The purity of the hydrogen source affects the purity of the gas produced. Typically, it is not desirable for the unintended impurity concentration to exceed 1 / 100,000. Hydrogen atoms are generated by dissociating a gas such as a hydrogen molecule by, for example, microwave plasma. The mixture of hydrogen atoms and molecules diffuses in the electron-induced gas. Hydrogen molecules are introduced directly into the electron-inducing gas. The hydrogen concentration ranges from 10: 1 to 50: 1 at a pressure of 10 Torr to 1 atm. At a pressure of less than 10 Torr, the flow rate of generated gas is low, which is not desirable.
At a pressure exceeding tm, the gas generation reaction does not proceed, which is inconvenient.

The Group V and Group VI sources introduced into the reactive gas in the gaseous state also need not be strictly specified.
Typical sources are resistive, convective heating, or thermal evaporation of constituent materials such as phosphorus, arsenic, selenium, tellurium. These materials are maintained at a temperature sufficient to produce the desired concentration of Group V or Group VI atoms for introduction into the reactive gas. Usually 150 to 30
A range of 0 degrees is appropriate. The lower limit temperature is V group or
Determined by the volatility of Group VI materials. The upper temperature limit is
It is determined by the decomposition temperature at which the precursor is formed. When heated at relatively low temperatures, the flow from low vapor pressure materials is not sufficient. However, for Group III and IV materials, non-thermal evaporation processes such as ion irradiation can be used.

[0010] The desired hydrogenated gas generated by the gas reaction is taken out by a technique such as continuous flow of a carrier gas or leakage of molecules to a device fabrication region, and is directly used for device fabrication. Accordingly, the use of a compressed gas cylinder for hydrogenation gas can be avoided.

The following example shows one example of specific conditions used in the gas generation stage in the present invention.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
In the quartz reactor shown in FIG. Reactor 1
It has an inner reaction chamber 2 having a small channel hole of 1/16 inch (1.6 mm) diameter and an outer jacket 3, and hydrogen gas is introduced into each of them.
High purity hydrogen gas (99.999%) is supplied to ports 4 and 5
Before being introduced into reactors 2 and 3 via Nanochem
Model LS-50 gas purifier (Nanochem System Inc.)
Is further purified. The flow rate of hydrogen is controlled by the flow controllers 6 and 7 from 100 sccm to 50 sccm.
It is adjusted in the range of 0 sccm. High purity (99.999
%) Arsenic small pieces (1/2 "x1") (12.25 mm x 2
4.5 mm)) 8 are introduced into the reactor 1.

A Tesla coil 9 as an electron source includes a cathode 10 having aluminum as a tip together with a nylon insulating ring 11. It is connected to the reactor 1 through a Teflon (registered trademark: polytetrafluoroethylene) insert 14. The イ ン チ inch (12.25 mm) diameter accessory 12 has an O-ring seal 13 between the quartz body and the nylon insulating ring 11. 10 degrees of vacuum
The air in the reactor 1 is drawn until the pressure becomes ^-4 . The arsenic small pieces 8 are heated by the vertical furnace 18 to evaporate arsenic. The temperature of the vertical furnace is adjusted in a range where the actual temperature of the chemical reaction is appropriate, typically from 150 to 300 degrees. Hydrogen is introduced into the reactor 1 from ports 4 and 5 at the desired flow rate and pressure (measured by the transducer 15), and the interior of the reactor 1 is maintained in a suitable range from 10 torr to 1 atm. When the Tesla coil 9 was operated under the above conditions, arsine was generated, and 17% by volume arsine was detected by measurement with a spectrophotometer.

[0014]

As described above, according to the present invention, in a device fabrication process including crystal growth, a precursor gas is generated by electron beam irradiation and used as it is for device fabrication, thereby providing highly toxic arsine. Alternatively, it is possible to provide a device manufacturing method and an apparatus thereof which do not require storing a large amount of a precursor gas such as phosphine.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a gas generation device used in a device manufacturing method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reactor 2 Inner reaction chamber 3 Outer jacket 4-5 Port 6-7 Flow controller 8 Arsenic small piece 9 Tesla coil 10 Cathode 11 Nylon insulating ring 12 1/2 inch diameter accessory 13 O-ring seal 14 Teflon insert 15 Transducer 18 Vertical furnace

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Ronald Alexandra Holland USA 07050 New Jersey Orange, Auston Road 184 (72) Inventor James Winfield Mitchell USA 08873 New Jersey Somerset, Kingsbridge Road 17 (56 ) References JP-A-2-58331 (JP, A)

Claims (6)

(57) [Claims] 1. A device manufacturing method including a crystal growth portion, comprising: supplying the precursor gas to a device for use in growing the crystal growth portion; and immediately before the step, mixing a gaseous mixture by electron beam irradiation. By maintaining the chemical reactivity inside, arsine and
Generating a precursor gas comprising a material selected from the group comprising phosphine . 2. The method of claim 1, wherein the device has a gallium arsenide layer. 3. The method according to claim 1, wherein said device comprises an integrated circuit. 4. The method of claim 1, wherein said gas mixture comprises a mixture of hydrogen and arsenic. 5. The method of claim 1, wherein said crystal growth portion is a III-V semiconductor material. 6. A group comprising arsine and phosphine.
Means for growing a crystal on a substrate using a precursor gas containing a material selected from the group consisting of: a gas material and a means for confining an accelerating electron source, and a means for generating the precursor gas, A device manufacturing apparatus, wherein a precursor gas generating means is configured to project the electrons onto the gas material in the region.