JPS61117194A - Vapor phase chemical reaction forming device - Google Patents

Abstract

PURPOSE:To improve the uniformity of the thickness of CVD films and to make uniform the properties of the CVD film on a wafer by combining a transparent quartz member, heating means, gas introducing means and discharge port as well as rotating mechanism so as to have a specific effect. CONSTITUTION:A reactive gas 13 is introduced widely through plural gas introducing nozzles 13 into a reaction furnace 11 so as to be introduced unformly from above and is blown to the wafer 20 so as to have the uniform concn. of the reactive gas over the entire region of the wafer in a CVD system of a tunnel type. The inside of a quartz tube 10 is uniformly heated by a heater 15 enclosed on the outside thereof. The wafer 20 is put into a wafer carrier 21 and is moved at a specified speed by a moving mechanism in the furnace 11 in the long axis direction. The reactive gas 13 introduced into the furnace 11 is discharged through each discharge pipe 14 at the bottom after the reaction. Then the difference in conditions is virtually eliminated in the relative relation between the reactive gas 13 and each wafer 20 and only the uniformity of the thickness of the CVD film in the single wafer and the uniformity of the physical and chemical properties of the formed film are consequently required to be taken into consideration.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) This invention is directed to CVD (Chemical Vapor
Deposi-11011; relates to a novel structure of a gas phase chemical reaction production, chemical vapor deposition,) device.

(Technical background of the invention and its problems) As shown in Fig. 4, a conventional LP (low pressure) CVO device stores a flat wafer in a horizontally long cylindrical reaction tube made of an inert material, such as quartz. Approximately 50 to 100 sheets of quartz 2 are placed on the quartz port 3 and heated to a predetermined temperature by a heater 4 surrounding the quartz reaction tube 1 from the outside. Then, the reaction gas 5 is introduced from one end of the quartz reaction tube 1 and evacuated from the other end using a vacuum pump (not shown) to reduce the pressure inside the reaction tube 1 to about 0.3 to 1.0 [TOR
R] (7) [Encircle L, TECVN (vapor phase chemical reaction) is being performed.

However, such conventional horizontal CvD equipment has
It has the following drawbacks: That is, the introduced gas flow (
Regarding 5), since the distance between the first wafer and the last wafer increases before and after the quartz boat 3, the uniformity of the GVD-generated film thickness becomes more important. Further, for the same reason, a reaction gas depletion phenomenon occurs, and there is a drawback that the properties of the CVD film differ between the wafers 2 placed before and after. In addition, the ends of the reaction tube 1 are not heated and can only be used in the center of the reaction tube 1 due to large temperature changes, and in order to improve the uniformity of the CVD l1g thickness, it can be used before and after the quartz port 3. If a temperature difference is applied to the heating of the heater 4, the physical properties of the CVD film of each unit will differ as a result.Furthermore, using the mean free path of the reaction gas molecules, Since the gas concentration between the sections is made uniform, in order to obtain practical uniformity, the reaction section pressure should normally be set at 1.0 [TOR
R] must be maintained below. For this reason, the CVD production rate is slow, there is a limit to the control of the combination reaction using a plurality of reaction gases, and there are also drawbacks that the range of application of the process is limited.

(Standard of the invention) This invention was made due to the above-mentioned circumstances,
The purpose of this invention is to improve the uniformity of CVD-generated film thickness,
It is an object of the present invention to provide a gas phase chemical reaction generation device that does not cause differences in the properties, particularly physical properties, of CVD films on wafers.

(Summary of the Invention) The present invention relates to a gas phase chemical reaction generating device, which includes a donut-shaped transparent quartz member divided into upper and lower parts to form a gas phase chemical reaction chamber, and an inner and an outer side of the quartz member. , a heating means that is divided into four parts, an upper part and a lower part, each of which can be independently controlled in temperature, and a plurality of gas introduction nozzles and exhaust ports installed at certain intervals in the gas phase chemical reaction chamber. , and a rotation mechanism for rotating the wafer and wafer carrier installed in the gas phase chemical reaction chamber.

(Embodiments of the Invention) In the present invention, in order to improve the drawbacks of the horizontal CVD apparatus as described above, a so-called tunnel type CVD method is adopted as shown in FIGS. 1(A) and 1(B). That is, since the main cause of the drawbacks of the conventional CVD method is the long movement distance of the reaction gas, in this invention,
As shown in FIG. 1(A), a reactor 11 is formed of a cylindrical quartz tube IO of infinite length, and a gas introduction nozzle 12 made of quartz is arranged at a certain section in the upper part of each reactor 11. Reaction gas 13 is introduced from above, and gas 13A is exhausted from exhaust pipes 14 provided at regular intervals at the bottom.

Further, a heater 15 is attached to the outside of each quartz tube IG so as to surround it, and heats the entire reactor 11 to a predetermined temperature. If the wafer 20 can be moved in the long direction at a constant speed V within the reactor 11, all of the drawbacks of the conventional Cv port method as described above can be solved. For this reason, the reaction gas 13 is widely and uniformly introduced from the −E side of the reactor 11 using a plurality of gas introduction nozzles 13, and sprayed so that the concentration of the reaction gas is uniform over the entire area of the wafer 20. At the same time, the inside of one quartz tube 10 is uniformly heated by a heater 15 surrounded outside. Then, the wafer 20 is placed in a Univer carrier 21 (or a case/soto) at a constant speed V
The reaction gas 1 is moved in the long direction within the reactor II by a moving mechanism (not shown) and introduced into the reactor 11.
3 is exhausted from each exhaust pipe 14 at the bottom after the reaction. By doing this, the reaction gas L3 and each wafer 20
There is almost no difference in terms of the relative relationship between
Only the homogeneity of chemical properties needs to be considered.

In order to realize this concept in an actual device, an infinitely long quartz tube 10 may be bent to form a ring shaped like a "floating donut," and the wafer 20 can be placed inside the donut-shaped reaction chamber formed by this. By rotating two wafer carriers loaded with wafers, it is possible to obtain the same effect as moving wafers in an infinite tunnel.

Next, a specific embodiment of the present invention will be described with reference to FIGS. 2(A) and 2(B).

The entire reaction chamber has a water-cooled structure and is composed of a cap-shaped SUS shroud (actually divided into a side cylindrical structure and an upper plate) 30 and a disc-shaped SOS base plate 31. A vacuum-resistant chamber is formed by sealing with a ring 32. When opening the reaction chamber, the shroud 30 is lifted by a lift mechanism (not shown), separated from the base plate 31, and placed on the rotating table 35.
The wafer 40 and wafer carrier 41 can be easily installed and taken out.

The reaction gas is introduced through a forest-like gas nozzle 33 made of quartz that is divided into four parts above the reaction chamber, and each tip of the nozzle 33 has a small hole 30A of about IIIlφ in diameter for uniformly dispersing the gas. There are multiple holes equally spaced on both sides.

In addition, the reaction gas in the reaction chamber is exhausted from the base plate 3.
This is carried out using exhaust boats 34 provided on the outer and inner peripheries of 1. Valves (not shown) for adjusting the exhaust speed are installed between each of the inner and outer ports and the vacuum pump.
The pressure balance within the reaction chamber can be freely adjusted.

On the other hand, the wafer 50 and wafer carrier 51 have a structure as shown, for example, in FIGS. A rotary table made of quartz is used in such a manner that the aligned wafers 50 can be installed vertically or horizontally, or with a free inclination angle vertically, horizontally, or at an intermediate angle to the rotation direction. 3
5. The single wafer ceria 51 has side plates 52A and 52B made of quartz on both sides, and a front plate 53A made of quartz at both ends.

It has a rear plate 53B and has a hollow tube shape. Slots 54 are provided at predetermined intervals on both sides of the side plates 52A and 52B, and a quartz rod 55 is mounted at the center bottom between the front plate 53A and the rear plate 53B. Slots 5B are also formed at intervals corresponding to the slots 54. The wafer 50 on one disk is placed in the slot 5 of the side plates 52A and 52B.
The wafers 50 are inserted into the wafer carrier 51, fall down, and stop when they hit the slots 56 of the quartz rods 55 mounted on the bottom, and in this way, a predetermined number of wafers 50 are loaded into the wafer carriers 51. The rotation speed of the rotating table 35 is controlled by an external rotation control unit (not shown) via a magnetic seal rotation introduction unit 36 under the base plate 31, and forward and reverse rotations are freely controlled. It has become. In addition, the wafer 50 is a lower heater cover 3 made of transparent quartz.
7 and a transparent reaction chamber upper cover 38 made of quartz. Lower heater 42゜Outer heater 43
．． The inner heater 44 is installed divided into four parts, and the temperature of each part can be controlled independently. It is necessary to freely realize the temperature distribution required in each process, and for this purpose, the temperature of each heater 41 to 44 is detected by a thermocouple (not shown) installed in each part, and the temperature is It can be controlled. When the reaction chamber is donut-shaped as in this example,
To make the temperature in the reaction chamber uniform, the temperature of the lower heater 42 is set higher than that of the upper heater 41, and the temperature of the outer heater 43 is set higher than the temperature of the inner heater 44, due to the difference in gas convection and heat radiation conditions. . Alternatively, in the silicon epitaxial growth process, for example, N-type (PH3
(gas use) If doped, the wafer 5 against the gas flow
The temperature in the downstream direction of 0 may be controlled to be lower than the temperature in the upstream direction. Each of the heaters 41 to 44 uses a tungsten or molybdenum coil to enable high-temperature epitaxial growth reactions (1200'O), and is designed so that the applied voltage can be lowered for use at low temperatures.9For example, 200 VIC and 450°C at 40VAC. Further, a cap-shaped heat insulating material 45 made of high-purity alumina or ceramic is installed on the outside of each heater 41 to 44 to prevent radiation of heat rays to the outside and the opposing surface. A purge gas is flowed between the heat insulating material 45 and the shroud 30, and this purge gas is exhausted from the lowermost support part of the reaction chamber upper cover 38 to the exhaust port 34, so that the reaction gas flows into the heater part. Preventing inflow.

In such a reaction chamber, solid matter after the reaction is covered with a quartz cover 38.
Since the quartz cover adheres to the interior of the shroud, it is necessary to periodically remove it and clean it. Therefore, a swing mechanism is employed in addition to the lift mechanism of the shroud 30, so that the quartz cover 38 can be easily attached and detached.

(Effects of the Invention) As described above, according to the CVD apparatus of the present invention, a uniform reaction gas can be supplied to each wafer.
o Excellent film uniformity and physical and chemical film quality homogeneity, eliminating the depletion phenomenon between each wafer. In addition, since the mean free path of one reaction gas molecule can be ignored, it can be used in a wide range of pressures (0, I Torr to 780 Torr), and by controlling the heater temperatures of 4 parts, a temperature pattern in the reaction chamber can be created according to each process. be able to.

Furthermore, the optimum temperature pattern, reaction pressure, gas concentration and partial pressure ratio, and rotational speed of the wafer carrier can all be set for each reaction process, allowing the process to be applied to metal CVD, which was difficult or impossible with conventional CvD methods.
, organometallic CVO, m-v group CVO, and silicon epitaxial growth.

[Brief explanation of drawings]

FIG. 1(A) is a structural diagram for explaining the present invention in detail, FIG. 1(B) is a sectional view taken along the line xx, and FIG. 2(A) is a vertical sectional view showing one embodiment of the present invention. , FIG. 7(B) is a plan sectional view thereof, FIG. 7(A) is a plan view showing an example of a wafer carrier used in the present invention, FIG. 7(B) is a Y-Y sectional view thereof, and FIG. 1 is a cross-sectional structural diagram showing an example of a CVD apparatus.

Claims (1)

[Claims] A donut-shaped transparent quartz member is divided into upper and lower parts to form a gas phase chemical reaction chamber, and the outside of this quartz member is divided into four parts: inner, outer, upper, and lower parts, each of which can be temperature controlled independently. , a plurality of gas introduction nozzles and exhaust ports installed at certain intervals in the gas phase chemical reaction chamber, and rotating wafers and wafer carriers installed in the gas phase chemical reaction chamber. 1. A gas phase chemical reaction generation device characterized by comprising a rotation mechanism for generating a gas phase chemical reaction.