JPH03212932A - Vacuum processing apparatus - Google Patents

Abstract

PURPOSE:To reduce a power loss and occurrence of dust, to make the film thickness distribution of a thin film excellent and to make a conveyance chamber small in size by a construction wherein a means of straightening the flow of gas is provided in a reaction chamber and the distribution of a halogen lamp and a conveyance mechanism are made appropriate. CONSTITUTION:A high-frequency electrode 24 is fitted to a first opening 22a of the chamber wall of a reaction chamber 22, with an insulator 25 of low permittivity interposed, so that it blocks up the opening 22a, while a gas straightening plate 32 is provided between a substrate heating electrode 28 and the side wall 22c of the chamber 22. Thereby a floating electrostatic capacity and a power loss are reduced, while nonuniformity in the flow of gas running through the chamber 22 is eliminated, and the film thickness distribution of a thin film formed on the surface of a wafer is made excellent. Besides, an elevation shaft of a lifter 29 is provided in a hole located at a position deviating from the center of the electrode 28, while a halogen lamp 37 is provided outside the chamber and in the vicinity of a quartz window 36 of a conveyance chamber 23, and further a conveyance mechanism 34 conveying a tray for the wafer is disposed only inside the chamber 23. According to this constitution, it is possible to make a temperature distribution excellent, to make the chamber 23 small in size and to make excellent the film quality of the thin film formed on the surface of the wafer.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a vacuum processing apparatus, and in particular,
This relates to a plasma CVD apparatus for manufacturing compound semiconductors.

(Conventional technology) A conventional vacuum processing apparatus is shown in FIG.

In the figure, in a reaction chamber 1, a high-frequency electrode 2 that is vertically movable and installed through the top plate Ia of a reaction chamber 1, and a substrate heating electrode 4 having a built-in sheathed heater 3 are arranged facing each other. has been done. An earth shield 5 is attached around the high frequency electrode 2 with a gap. A gas introduction pipe 6 is connected to the high-frequency electrode 2, and the gas that has passed through the gas introduction pipe 6 passes through a passage (not shown) in the high-frequency electrode 2, and then passes through a jet nozzle (not shown).
(not shown) in the direction of the substrate heating electrode 4, and is then exhausted from an exhaust lower provided on the side wall of the reaction chamber 1. A lid (not shown) that can be raised and lowered is provided in a plurality of holes (not shown) around the center axis of the substrate heating electrode 4, and the lifter transfers a wafer tray to the substrate heating electrode 4, which will be described later. will be held. A chain roller conveyance mechanism 8a is disposed slightly above the substrate heating electrode 4. Next to the reaction chamber 1, a transfer chamber 10, which also serves as a loading/unloading chamber, is connected via a gate valve 9. A chain roller transport mechanism 8b is disposed within the transport chamber IO, and a wafer tray II carrying wafers (not shown) is mounted on the chain roller transport mechanism 8b. Further, a /10 gen lamp 12 is disposed above the chain roller transport mechanism 8b in the transport chamber IO. In addition, in the figure, 13 is a high frequency power supply connected to the high frequency electrode 2,
14 is a gas introduction valve provided in the gas introduction pipe 6.

Next, the operation of the vacuum processing apparatus will be explained.

First, the wafer tray 11 carrying wafers is placed on the chain roller transport mechanism 8b in the transport chamber 10, and then the transport chamber IO is evacuated.

Next, the wafers on the wafer tray 11 are heated to 100 to 200° C. using a halogen lamp 12 .

Next, the gate valve 9 is opened, and the wafer tray 11 carrying the wafer is transferred to the chain roller transport mechanism 8 in the transport chamber 10.
b to the chain roller transport mechanism 8a in the reaction chamber 1, and then placed on the substrate heating electrode 4 by a lifter.

Thereafter, the wafers on the wafer tray 10 are heated to 200 to 400° C. by the substrate heating electrode 4 .

Finally, the gas introduction valve 14 is opened, gas is ejected from the ejection port of the high-frequency electrode 2, and plasma is generated between the high-frequency electrode 2 and the substrate heating electrode 4 to form a thin film on the surface of the wafer.

Note that when returning the wafer on which the thin film has been formed to the transfer chamber 10, the operation opposite to that described above is performed.

(Problem to be Solved by the Invention) In the conventional vacuum processing apparatus, as mentioned above, the high frequency electrode 2 is surrounded by the earth shield 5 with a gap, so the barber capacitance due to this gap is large, and power consumption is reduced. A problem has arisen that increases the number of Further, as mentioned above, the gas ejected from the ejection port (not shown) of the high-frequency electrode 2 in the direction of the substrate heating electrode 4 is exhausted from the exhaust lower; Since no special means for adjusting the flow is provided, the gas flow becomes uneven, resulting in a problem that the thickness distribution of the thin film formed on the surface of the wafer deteriorates. Furthermore, since the chain roller transport mechanism 8a is also disposed in the reaction chamber 1 as described above, a problem arises in that dust is generated from the chain roller transport mechanism 8a and the like. Furthermore, since the halogen lamp 12 is disposed within the transfer chamber 10, there arises a problem that the transfer chamber IO becomes larger.

The purpose of this invention is to solve the conventional problems, reduce power dissipation, generate less dust, improve the thickness distribution of the thin film, and make it possible to downsize the transfer chamber. An object of the present invention is to provide a vacuum processing device.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a vacuum processing apparatus in which a reaction chamber and a transfer chamber are connected via a gate valve.
The reaction chamber includes a high-frequency electrode having a reaction gas passage therein, which is attached to a first opening in the chamber wall through an insulator with a low dielectric constant so as to close the first opening, and a second opening in the chamber wall. A substrate heating electrode with a built-in heater is attached to the chamber wall so as to close it and protrudes into the chamber at a distance from other parts of the chamber wall, and is disposed facing each other in the chamber.
A gas rectifying plate is provided between the substrate heating electrode and other parts of the chamber wall, and an exhaust port for exhausting the reaction gas that has passed through the gas rectifying plate is provided in the chamber wall. A lifting shaft of a lifter for transferring the wafer tray whose front and back surfaces have been blasted and roughened is provided in the hole provided at the position where the wafer tray is placed. A quartz window is provided on the chamber wall, a heating lamp is provided outdoors near the quartz window, and a cassette for storing the wafer tray is placed next to the transfer chamber. It is characterized in that the provided cassette chambers are communicated with each other.

(Function) In this invention, as described above, the high-frequency electrode is attached to the first opening of the chamber wall of the reaction chamber via an insulator with a low dielectric constant so as to close the first opening, so that stray static Smaller capacity and less power dissipation. In addition, a gas rectifying plate is provided between the substrate heating electrode and other parts of the chamber wall, and the reaction gas that has passed through this gas rectifying plate is exhausted from the exhaust port provided in the chamber wall. The gas flow becomes even, and the thickness distribution of the thin film formed on the wafer surface is improved. Furthermore, since the lifting shaft of the lifter is provided in a hole provided eccentrically from the center of the substrate heating electrode, the sheathed heater can be wound around and built into the center of the substrate heating electrode. The substrate on the wafer tray placed thereon can be sufficiently heated, and its temperature distribution can be improved. Furthermore, since the heating lamp is disposed outdoors near the quartz window provided on the wall of the transfer chamber, the transfer chamber can be made smaller. Furthermore, since the transport mechanism for transporting the wafer tray is provided only within the transport chamber, dust generation in the reaction chamber is reduced, and the quality of the thin film formed on the surface of the wafer is improved.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a vacuum processing apparatus according to an embodiment of the present invention, in which a reaction chamber 22 and a transfer chamber 23 are connected via a gate valve 21, and a side of the transfer chamber 23 is The cassette chamber 38 is in communication. First, in the reaction chamber 22, a high-frequency electrode 24 is attached to an opening 22a at the top via an insulator 25 made of Teflon (trademark) with a low dielectric constant, and one side of the high-frequency electrode 24 is located inside the reaction chamber 22. There is. A part of the outer periphery of the high-frequency electrode 24 is surrounded by an insulator 25 made of Teflon (trademark) with a low dielectric constant, so that stray capacitance is reduced and power consumption is reduced.

Further, while a high frequency power supply 26 is connected to the high frequency electrode 24, a gas introduction pipe 27 is also connected, and the gas flowing through the gas introduction pipe 27 passes through a passage (not shown) in the high frequency electrode 24. substrate heating electrode 2 from the spout (not shown)
It is ejected in 8 directions. The substrate heating electrode 28 is attached to the opening 22b at the bottom of the reaction chamber 22, projects into the reaction chamber 22 at a distance from the side wall of the reaction chamber 22, and faces the high frequency electrode 24 at a predetermined distance. As shown in detail in FIGS. 2 and 3, the substrate heating electrode 28 is provided with a hole 28a at a position eccentric from the center by a predetermined distance, and is raised and lowered into this hole 28a by an elevator (not shown). The lifting shaft 29a of the lifter 29 is inserted. Lifter 29
At the tip of the lifting shaft 29a, there is a base 29b made of nickel,
and claws 29b made of alumina extending in parallel from both ends of the fork part 29b, which is formed in a U-shape, is attached, and the center of the substrate heating electrode 28 is positioned between the claws 29b2. It has become. A groove 3o is formed in the upper surface 28b of the substrate heating electrode 28, in which the fork portion 29b is buried when the lifter 29 is lowered. Therefore, when the lifter 29 is raised, the fork portion 29b protrudes and retracts from the upper surface 28b of the substrate heating electrode 28, but on the other hand, when the lifter 29 is lowered, the fork portion 29b is buried in the groove 3o. A sheathed heater 31 is built in the substrate heating electrode 28, and the sheathed heater 31 is also built in the center of the substrate heating electrode 28. Therefore, the substrate heating electrode 28
The temperature of the wafer (not shown) on the wafer tray (described later) placed thereon rises sufficiently, and its temperature distribution becomes better. Returning to FIG. 1 again, a ring-shaped gas rectifying plate 32 is provided between the substrate heating electrode 28 and the side wall 22c of the reaction chamber 22, and the reaction chamber 22 below the gas rectifying plate 32
An exhaust port 33 is provided in the side wall 22c of No. 2, so that the gas that has passed through the gas rectifying plate 32 is exhausted from the exhaust port 33.

Next, a transfer mechanism 34 is disposed within the transfer chamber 23, and as shown in detail in FIGS. 4 and 5, the transfer mechanism 34 has an arm mechanism 34b attached to the tip of its rotating shaft 34a. A support stand 34c is attached to the tip of the arm mechanism 34b.

A wafer tray 35 with wafers (not shown) placed thereon is placed on the support stand 34c, and the front and back surfaces of the wafer tray 35 are roughened into a matte finish by blasting. A transparent quartz window 36 is attached to the wall of the transfer chamber 23, and a halogen lamp 37 is placed outside near the quartz window 36. Light from the halogen lamp 37 passes only through the quartz window 36 and is directed toward the wafer. The wafers on the tray 35 are irradiated, thereby causing the wafers to be preheated in the transfer chamber 23. Note that the type of heating lamp does not necessarily have to be a halogen lamp.

Next, a cassette 39 is provided in the cassette chamber 38, and a wafer tray 35 is accommodated in the cassette 39.

The operation of the above embodiment will be explained.

First, the reaction chamber 22 is evacuated, then the wafer tray 35 on which the wafers are placed is accommodated in the cassette 38, and then the cassette chamber 24 and the transfer chamber 23 are evacuated.

Next, the wafer tray 35 is transported into the transport chamber 23 by the transport mechanism 34, stopped, and then the halogen lamp 37
The wafers on the wafer tray 35 are irradiated with light through the quartz window 36, and the wafers are heated to 100 to 20
Preheat to 0°C.

In this case, since the halogen lamp 37 is installed outside near the quartz window 36 provided on the wall of the transfer chamber 23,
The transport chamber 23 can be downsized.

Next, the gate valve 21 is opened, the wafer tray 35 is transported from the transport chamber 23 into the reaction chamber 22 by the transport mechanism 34, and then the wafer tray 35 is placed on the substrate heating electrode 28 by the lifter 29.

After closing the gate valve 21, the wafers on the wafer tray 35 placed on the substrate heating electrode 28 are
Heat to 00°C. At this time, the lifter 29 is inserted into the hole 28a provided at a position eccentric from the center of the substrate heating electrode 28.
Since the lifting shaft 29a is provided, the sheathed heater 31 can be wound around and built into the center of the substrate heating electrode 28. Therefore, the wafer tray 3 placed on the substrate heating electrode 28 can be
The wafer on 5 can be sufficiently heated and its temperature distribution can be improved.

Finally, after closing the gate valve 21, gas is ejected from the ejection port of the substrate heating electrode 24, and the plasma generated between the high frequency electrode 24 and the substrate heating electrode 28 forms a thin film on the surface of the wafer. At this time, since the high-frequency electrode 24 is attached to the first opening 22a of the chamber wall of the reaction chamber 22 via the insulator 25 with a low dielectric constant so as to close the first opening 22a, the barber capacitance becomes small. Power consumption is reduced. In addition, the substrate heating electrode 28 and the side wall 22c of the reaction chamber 22
A ring-shaped gas rectifying plate 32 is provided between the gas rectifying plate 32 and an exhaust port 33 on the side wall 22c of the reaction chamber 22 below the gas rectifying plate 32. Since the gas is exhausted from the reaction chamber 33, the flow of gas in the reaction chamber 22 becomes even, and the thickness distribution of the thin film formed on the surface of the wafer is improved. Furthermore, since the transport mechanism 34 is not provided in the reaction chamber 22, the generation of dust in the reaction chamber 22 is reduced, and the quality of the thin film formed on the surface of the wafer is improved.

Incidentally, when returning the wafer on which the thin film has been formed to the cassette chamber 24, the operation opposite to that described above is performed.

By the way, the above embodiment is based on plasma CVD for compound semiconductors.
It is often used in plasma CVD equipment for silicon, vacuum processing equipment for glass substrates, plasma etching equipment, plasma polymerization equipment, etc.

(Effect of the invention) This invention provides the following effects.

(2) Since the high-frequency electrode is attached to the first opening in the wall of the reaction chamber via an insulator with a low dielectric constant so as to close the opening, the barber capacitance is reduced and power consumption is reduced.

■A gas rectifying plate is provided between the substrate heating electrode and other parts of the chamber wall, and the reaction gas that has passed through this gas rectifying plate is exhausted from the exhaust port provided in the chamber wall, so that it flows inside the reaction chamber. There is no bias in the gas flow, and the thickness distribution of the thin film formed on the wafer surface is improved.

■Since the lifting shaft of the lifter is provided in a hole located eccentrically from the center of the substrate heating electrode, the sheathed heater can be wound and built into the center of the substrate heating electrode.
The substrate on the wafer tray placed on the substrate heating electrode can be sufficiently heated, and the temperature distribution can be improved.

(2) Since the heating lamp is placed outside near the quartz window provided on the wall of the transfer chamber, the transfer chamber can be made smaller.

■The transport mechanism that transports the wafer tray is installed only inside the transport chamber and not inside the reaction chamber, which reduces the generation of dust in the reaction chamber and prevents the formation of a thin film on the surface of the wafer. The film quality improves.

[Brief explanation of drawings]

Fig. 1 is an overall view showing the entire embodiment of the present invention, Fig. 2 is a plan view showing details of the substrate heating electrode used in the embodiment of the invention, and Fig. 3 is a cut along line II in Fig. 2. FIG. 4 is a plan view of a conveyance mechanism used in an embodiment of the present invention, and FIG. 5 is an elevational view of the conveyance mechanism. FIG. 6 is an overall view showing a conventional vacuum processing apparatus. In the figure, 21... Gate valve 22... Reaction chamber 22a... Opening at the bottom of the reaction chamber (first opening) 22b... Opening at the bottom of the reaction chamber (second opening) opening) 23... Transfer chamber 24... High frequency electrode 25... Insulator 28... Substrate heating electrode 28a... Hole 29 of the substrate heating electrode... ... Lifter 29a ... Lifter lifting shaft 31 ... Sheathed heater 32 ... Gas rectifying plate 33 ... Exhaust port 34 ... Transport mechanism 35 ...・Wafer tray 36...Quartz window 37...Halogen lamp 38...Cassette chamber

Claims (1)

[Claims] 1. In a vacuum processing apparatus in which a reaction chamber and a transfer chamber are connected via a gate valve, the reaction chamber is provided with a first opening in the chamber wall through an insulator with a low dielectric constant so as to close the first opening. a high-frequency electrode having a reaction gas passage therein; and a substrate heating electrode with a built-in heater attached to a second opening in the chamber wall so as to close it and protruding into the chamber at a distance from other parts of the chamber wall. are arranged facing each other in the chamber, and a gas rectifying plate is provided between the substrate heating electrode and other parts of the chamber wall, and an exhaust port for exhausting the reaction gas that has passed through the gas rectifying plate is located in the chamber. In a hole provided in the wall and located eccentrically from the center of the substrate heating electrode,
A lifting shaft of a lifter is provided to transfer the wafer tray whose front and back surfaces have been blasted to have a rough texture, and the transfer chamber is provided with a transfer mechanism for transferring the wafer tray. A quartz window is provided on the chamber wall, a heating lamp is provided outdoors near the quartz window, and a cassette chamber equipped with a cassette for accommodating the wafer tray is connected to the side of the transfer chamber. A vacuum processing device characterized by: