JPS5844712A - Heat treatment device for semiconductor - Google Patents

Abstract

PURPOSE:To prevent the dissociation of As from a GaAs substrate by introducing the GaAs substrate and an As compound, the pressure of equilibrium As thereof is higher than the substrate, into the same reactor and annealing the substrate and the compound. CONSTITUTION:A cover 2 is connected to the upper section of the reactor 1 and the reactor is formed in hermetically sealed shape, a sample base 3 is fitted into the reactor, and a thermocouple 4 is disposed to the lower surface of the sample base 3. A capillary tube 5 for sucking an inert gas is set up to one side surface of the reactor 1 and a capillary tube 5' for exhaust to an opposite side surface, a capillary tube 9 for adjusting the pressure of As is fitted on its midway of the capillary tube 5, and cocks 7-9 are mounted to each capillary tube. A resistance heating furnace 12 for heating the whole reactor 1 in an externally heating type is installed, and can be moved. According to said constitution, the GaAs substrates 13 to which an impurity is injected completely and the AsSi 14 as a reactant are placed onto the sample base 3, the inert gas is properly introduced, and the substrates and the AsSi are thermally treated. Consequently, danger in case of operation can be prevented because the dissociation of As from the substrates 13 is obviated and a large amount of As gas are not generated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compound semiconductor manufacturing apparatus, and more particularly to a heat treatment apparatus for activating a gallium arsenide (Ga) semiconductor substrate into which impurity ions have been implanted.

GaAs semiconductors, which are one of the chemical compound semiconductors, have attracted attention because of their higher electron mobility than silicon semiconductors, and have already been put to practical use as optical halftone devices and microphone wave devices. As the impurity doping technology carried out in the semiconductor manufacturing process, the ion implantation method is generally used because it can obtain a good impurity distribution and has good reproducibility. In some cases, it is necessary to activate the ion implantation 1ktca@, and therefore the thermal part II (
However,
Because the GaM S compound has a large dissociation pressure, it is
If the arsenic was used, the arsenic (S) would dissociate.

Problems such as oxidation also occur. In order to prevent such dissociation and oxidation, various improvements have been made to 7-diyl in the prior art.

For example, using a protective trowel! kM7 In Neel's method, silicon oxide (810 m), silicon/nitride Qkt (
A protective film such as 811N4) is formed and the bales are annealed, but this method cannot completely avoid the dissociation of Ichimuhatake, and semi-insulating films doped with PM (Cr) The GaAs substrate t is Cr
A phenomenon occurs in which is adsorbed to the retention Ii film.

Furthermore, there is a problem that stress is generated due to the difference in thermal expansion coefficient between the GaA-substrate and the thermal expansion layer, which changes the properties of the ion-implanted layer.

In addition, in the case of a closed tube method (or sealed tube method) in which a KGaA substrate and a metal layer are sealed in the same tube for 7 hours, it is difficult to control the pressure of the layer released from the metal layer. On top of this, there is a five-layer layer that adheres to the surface of the GaAs substrate and the inner wall of the tube during cooling and contaminates it, while K is difficult to handle.

In the present invention, in order to prevent the dissociation and oxidation of mulch, which is a problem when a GaA-substrate is annealed at 800"C or higher for 7 days, a mulch compound having a higher dissociation pressure than a GaAs compound at the annealing temperature is used. Placed in the same reaction system, the pressure from the GaAs substrate increases
The purpose is to provide a heat treatment apparatus that is simple, has little operational risk, and has good reproducibility.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

The attached drawings schematically show the heat treatment apparatus according to the present invention.
The reactor 1, which consists of a heating device and a piping control system for atmosphere #I411, is equipped with a lid 2 on the top [
A sealed mK shadow is formed, and a nimate sample stage 3 is provided inside the mK, and a thermocouple 4 is disposed on the lower surface of the carpet sample stage 3 so that its tip is in contact with it. Here, the reactor 1 is generally made of quartz, but may also be made of alumina (mul*Oa), carbon, or other heat-resistant materials, and the lid 2 & It is designed with a relatively large 11K and heavy material so that it can be held in place, but it is possible to further increase the airtightness by applying pressure using weights, springs, etc., or by forming grooves in the retaining part. You can try matching multiple times.

A first capillary tube 5 for inert gas injection is attached to one side of the reactor, and a second capillary tube for exhaust gas is attached to the opposite side. A third capillary tube 6 is attached to each capillary tube, and each capillary tube has a first cock 7 for displacing the gas in the reactor l and adjusting the gas pressure.
．． A second cock 8 and a third hook 9 are provided.

The reason for using a capillary tube here is that it is effective in preventing gas backflow within the tube. In addition, in Figure 5, 10°1
σ represents a flow rate needle, and 11 represents a pressure needle. As a heating device, a resistance heating furnace 12 is provided to externally heat the entire reactor, and this is movable. During heating, it is shown in the figure. Move it in the direction of the white arrow.

With the above configuration, first, the GaAm substrate 13 that has been implanted with impurity ions and the powder of the bulk silicon compound (Muhata 81) 14 as a reactant are placed on the sample stage 3 in the reaction apparatus 1, and then the Open the first cock 7 and the 5Hz book 8, open the third cock 9, and pour inert gas such as argon (Mr) from one end of the first capillary device (in the direction of the solid line arrow in the figure). The inside of the chamber is equipped with murium gas. After preventing the GaAa substrate from oxidizing as described above, the heating furnace 12 is then moved to a position covering the reaction apparatus 1 (in the direction of the white arrow in Fig. C), and temperature rise is started. Here, 1 reactant and the musgi compound at L°C are G at 700°C or higher.
Since it generates a S pressure higher than the equilibrium S pressure of the aAs compound, the temperature of the GaA substrate (850°C) is
), close the second cock 8 and press
Make sure the gas doesn't leak out, and put it on. g3 cook 9
The pressure inside the reactor 1 is adjusted to a predetermined pressure while adjusting the opening degree of the first book 7, and depending on the case, vI is adjusted to a predetermined pressure.
! After closing the push button i1, the pressure is adjusted only once using the third book 9.

After the annealing is completed, first open the second cock 8, close the third book 9, open the first cock 7, and gradually replace the inside of the reactor 1 with the gas while the temperature drops.

At this time, it is necessary to be careful about the appropriateness of the substitution of the mu gas. For example, if K is replaced rapidly while the temperature is still high (in the temperature range where the dissociation of mu gas is progressing), GaAs
There is a risk that Mu1 will dissociate from the substrate, and on the other hand, if the replacement is not completed until the temperature reaches a low temperature, Mu1 gas will adhere and G
There is a risk of contaminating the printed circuit board. Therefore, it is necessary to thoroughly understand the operating conditions through experiments in advance.

In this example, a compound [Mu81] was used as a reactant, but any substance that generates a pressure higher than the equilibrium pressure of the G1 compound in the temperature range used may be used. may be used.

In other examples, high frequency heating was tried as a heating method. In other words, a carbon sample stage is provided in one reaction device, a GaAs substrate and a Mu-81 compound are placed on the skeleton specimen stage, and high frequency heating is performed.
The shape and dimensions of the sample stand on which the compound is placed and the sample stand on which the m81 compound is placed are set appropriately.

It was possible to control the heating characteristics such as the rate of temperature increase and the temperature reached, and even better results could be obtained with KJL.

The present invention provides one or more KGa in the same reactor as established.
AsJll+ plate and dazzling GaAs substrate, equilibrium and mu S
Because it is annealed by adding a high-pressure arsenic compound.

It is possible to prevent the dissociation of gas from the GaAs substrate, and there is no danger of generating a large amount of gas, unlike when using a metal substrate, and there is less danger in heat treatment, for example, it is possible to conduct heat treatment for a long time. As the temperature increases, SaraK uses a pipe to prepare the atmosphere, making it more reusable (and also making good use of inert gas to prevent oxidation and mu gas contamination). Although it is possible, the effect is extremely large.

[Brief explanation of the drawing]

The figure is a schematic diagram of a heat treatment apparatus according to the present invention. 1... Reactor, 2... Lid, 3... Sample stand. 4...Thermocouple, 5 v 5' e 6... Capillary, 7
98 #9...cock, to, 1σ...flow rate needle. DESCRIPTION OF SYMBOLS 11... Pressure needle, 12... Heating furnace, 13-Ga Mu substrate, 14... Mu81 compound patent applicant Fujitsu Ltd. Kinsha

Claims (3)

[Claims] (1) A heat treatment apparatus for gallium arsenide (GaAs) compound semiconductors is provided with a hermetically sealed reaction apparatus having an engaged lid, a sample stage and a thermocouple are disposed inside the reaction apparatus, and a sample stage and a thermocouple are disposed inside the reaction apparatus. Capillaries for introducing and discharging inert gas are connected to opposite sides of the device, and the capillary for introducing inert gas is connected to another capillary for pressure regulation, and each capillary is attached with a hook. On the other hand, a semiconductor thermal nine-layer device, characterized in that a heating furnace covering the reaction device is movably provided. (2) Inside the reactor, Ga moo & plate, G
A sample stage was provided to simultaneously hold the monomer compound, which has a higher equilibrium dissociation pressure than the mono-compound, and a pipe was provided to introduce an inert gas into the reaction apparatus as appropriate during the thermal treatment 8. A semiconductor mulling device according to claim 11111, characterized in that: (3) A patent claim characterized in that the sample stage in the skeleton reaction scissors is made of carbon or silicon-based silicon, and a high-frequency power generator is provided to heat the sample stage outside the reactor. A semiconductor heat treatment apparatus according to item 11111.