JPH0689444B2 - Thin film forming equipment - Google Patents

Description

The present invention relates to a thin film forming apparatus, and more particularly, to a thin film forming apparatus provided with a mechanism for preventing peeling of a thin film formed on an inner exposed surface in a reaction tank. Regarding the device.

(Prior Art) The thin film forming technology for forming a thin film on a substrate such as a semiconductor wafer is one of the most important process technologies in the semiconductor manufacturing process for high integration, high functionality and high reliability of semiconductor devices. Is.

Conventionally, as a thin film forming apparatus, a CVD (Chemical Vapor Deposition)
Position) equipment, sputtering equipment, vacuum deposition equipment, etc. are known, but in each case a reaction gas is introduced into the reaction tank and a thin film is formed on the substrate placed in the reaction tank by the reaction components of this reaction gas. It is a thing.

(Problems to be Solved by the Invention) In the thin film forming apparatus as described above, the particles generated by the reaction gas are not only the substrate which is a symmetrical object of processing but also the internal exposed surface in the reaction tank, such as the substrate holder or the reaction layer. A thin film is formed by adhering to the surfaces of the inner wall and the partition walls of the processing chamber.

By the way, in such a thin film forming apparatus, the substrate may be heated to a predetermined temperature to perform the film forming process. In such a case, when the substrate is brought into contact with a heater or the like to be heated,
Since the inside of the reaction tank is a vacuum atmosphere, heat conduction deteriorates even with a slight gap, and there is a problem that it is difficult to uniformly heat the substrate to a predetermined temperature. Further, for example, when it is attempted to heat with an infrared lamp or the like, there is a problem that particles generated by the reaction gas adhere to the infrared lamp or the like to block infrared rays.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a thin film forming apparatus capable of heating a substrate to a predetermined temperature accurately and uniformly.

[Structure of the Invention] (Means for Solving Problems) A thin film forming apparatus of the present invention is a thin film for performing a film forming process by moving a substrate into a vacuum chamber and sequentially guiding the substrate to a plurality of independent processing chambers. In the forming apparatus, a plurality of substrates are arranged in a concentric circle and rotated, a transfer plate, a pressure plate having substantially the same diameter as the transfer plate and airtightly pressing the transfer plates, and the substrate at a predetermined position of the transfer plate. And a heater block which is provided on the back side of the substrate held at a predetermined position by the clip and preheats the substrate, and which has a gas flow passage through which a sputtering gas flows, The heated sputtering gas flowing in the gas channel is provided so as to be located on the back surface of the substrate. And a thin film forming mechanism for introducing the sputtering gas into plasma and causing the sputtering gas to act on the target to deposit particles flying from the target on the substrate. It is a thing.

(Operation) In the thin film forming apparatus of the present invention, the heater block has a gas flow passage through which the sputtering gas flows, and the heated sputtering gas flowing through the gas flow passage is positioned on the back surface of the substrate. It is configured to be introduced into the processing chamber from the provided outlet. Therefore, the substrate can be heated to a predetermined temperature accurately and uniformly by using the heated sputtering gas. Further, by heating with the sputtering gas, it is possible to prevent the pressure in the processing chamber from rising undesirably.

(Example) An example in which the present invention is applied to a magnetron sputtering apparatus will be described below.

A wafer processing chamber, for example, a wafer loading / unloading chamber 2, an etching processing chamber 3, a wafer heating chamber 4, a first sputtering processing chamber 5, and a second wafer processing chamber, each of which has a cylindrical shape, are provided in a cylindrical reaction tank 1.
The sputter processing chambers 6 are juxtaposed in the order of semiconductor wafer processing steps. Then, the semiconductor wafer is transferred from the wafer loading / unloading chamber 2 to the reaction tank 1 by a wafer transfer device (not shown).
The semiconductor wafers are inserted into the chambers and subjected to a predetermined process while being sequentially transferred between the process chambers. On the other hand, semiconductor wafers that have been sequentially processed are taken out from the wafer loading / unloading chamber 2 and new semiconductor wafers are inserted.

A more specific structure of the sputter processing chamber will be described with reference to FIG.

A sputter electrode portion 7 is provided in the sputter processing chamber 5 in parallel with the inner wall surface of the reaction tank 1, and a semiconductor wafer 8 is arranged facing the sputter electrode portion 7.

A cylindrical partition wall 9 extends from the inner wall of the reaction tank 1 on the rear surface of the sputter electrode portion 7 so as to cover most of the side surface of the sputter electrode portion 7.

A gap is provided between the front edge of the partition wall 9 and the inner wall of the reaction tank 1 so that the atmospheric gas in the reaction tank 1 can flow between the processing chambers.

The sputter electrode portion 7 is arranged so as to surround the target 10 having a reverse conical ring-shaped sputter surface, one disk-shaped one pole, for example, the N pole 11 arranged at the center of the target 10, and the outer peripheral portion of the target 10. The other pole of the ring, for example, the S pole 12
The magnetic poles 11 and 12 form an arc-shaped magnetic field A near the sputtering surface of the target 10. The arc-shaped magnetic field A has a function of temporarily confining generated plasma particles, which will be described later.

In this embodiment, an example of forming a thin film of aluminum on the semiconductor wafer 8 is shown, and high-purity aluminum is used as the material of the target 10.

In the gap between the front edge of the partition wall 9 and the inner wall surface of the reaction tank 1, a rotatable disc-shaped transfer plate 15 holding the semiconductor wafer 8 in a wafer fixing hole 13 with a clip 14 and the partition wall 9 of the transfer plate 15 are provided. A disc-shaped pressure plate 16 that is located on the surface side and presses the transfer plate 15 by a contact mechanism (not shown) is provided. These transfer plates 15 and pressure plates 16
And the inner wall surface of the reaction tank 1 are attached so as to be separable from each other. When the semiconductor wafer 8 is moved to another processing chamber, for example, the second sputtering processing chamber 6, the pressure plate 16 is retracted to the partition 9 side and transferred. The plate 15 is made movable. The state shown in the figure shows the state during the sputtering process, and shows the state in which the transfer plate 15 is pressed by the pressure plate 16 and its movement is restricted.

A heater block 17 for preheating the wafer is arranged on the rear surface of the semiconductor wafer 8, and a sputtering gas introduction pipe 18 is provided so as to penetrate the heater block 17. Sputtering gas flows through the gas introduction pipe 18 and flows into the reaction tank 1 through an outlet provided on the outer periphery of the back surface of the semiconductor wafer 8.

The reaction tank 1, the partition wall 9, the magnetic poles 11 and 12, the transfer plate 15, and the pressure plate 16 are made of a metal material such as stainless steel, and a stainless steel wire is formed on the surface thereof, that is, the exposed surface inside the sputtering processing chamber. A metal grid network 19 formed in a grid shape is welded. This metal grid
19 is constructed by arranging stainless steel wires having a diameter of about 1 mm in parallel at a pitch of about 5 mm, and arranging the same metal wires in a zigzag pattern at equal intervals.

According to the sputtering apparatus having such a configuration, after the semiconductor wafer 8 is transferred into the sputtering processing chamber 5, the reaction tank 1
A high vacuum such as 10 ⁻⁷ Torr is set in the inside by a vacuum pump 20, and a high-temperature sputtering gas such as argon gas is introduced from the gas introduction pipe 18. At this time, the heat of the sputtering gas is transferred to the semiconductor wafer 8 via the heater block 17 to heat it. Next, electric power is applied to the target 10 at an appropriate timing according to a predetermined program to turn the sputtering gas introduced into the reaction tank 1 into plasma near the target 10. The plasma-generated sputtering gas is temporarily confined in the shape of a donut in the vicinity of the sputtering surface of the target 10 by the magnetic field A generated in the vicinity of the target 10, as shown by B in the figure.
The aluminum particles are knocked out of the target 10 by colliding with. The aluminum particles that have been knocked out fly into the sputtering processing chamber 5, and a part of the flying particles is emitted from the semiconductor wafer 8
Depositing and depositing on top achieves thin film formation of aluminum.

By the way, the particles flying from the target 10 are not limited to the semiconductor wafer 8 which is a symmetrical object, but also the partition wall 9, the magnetic poles 11 and 12,
Although a thin film is also formed by depositing on the internal exposed surface of the pressure plate 16 and the like, a metal lattice network 19 is welded to the internal exposed surface 21 as shown in FIG.
19 A large number of irregularities on the surface increase the contact area between the metal lattice network 19 and the thin film 22 and increase the adhesion between the two, and the metal lattice network 19 uses stainless steel with excellent thermal conductivity. Therefore, the temperature difference between the thin film 22 and the internal exposed surface 21 can be removed promptly, and the internal stress generated in the thin film is greatly reduced due to the temperature difference between the thin film 22 and the internal exposed surface 21. It does not peel off.

Therefore, there is no problem that the peeling pieces float and adhere to the semiconductor wafer or induce abnormal discharge near the sputter electrode surface.

By the way, as a method of attaching the metal lattice network 19, the inner exposed surface may be directly welded as in the above-described embodiment, or a mounting jig such as a hook-like member may be provided on the inner exposed surface so as to be detachably attached to the metal. With the structure in which the grid-making net is attached, maintenance work such as cleaning inside the reaction tank becomes very easy.

The present invention is not limited to the above-described embodiment, and any means for forming irregularities on the inner exposed surface may be used. For example, as shown in FIG. 3, a large number of shallow grooves 23, for example about 2 m wide, may be formed on the inner exposed surface 21.
You may form m and a depth of about 1 mm vertically and horizontally.

It is needless to say that the present invention can be applied to any thin film forming apparatus such as a CVD apparatus or a vacuum vapor deposition apparatus for introducing a reaction gas into a reaction tank to form a film.

[Effects of the Invention] As described above, according to the thin film forming apparatus of the present invention, the substrate is heated using the processing gas, so that the substrate can be heated to a predetermined temperature accurately and uniformly.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a sputtering processing chamber of a magnetron sputtering apparatus according to an embodiment of the present invention,
FIG. 2 is a partially enlarged sectional view of FIG. 1, FIG. 3 is a partially enlarged view showing an embodiment of the present invention, and FIG. 4 is a partially enlarged view showing another embodiment. 1 ... Reactor, 9 ... Partition, 5 ... Sputtering chamber, 8
…… Semiconductor wafer, 10 …… Target, 19 …… Metal grid network, 21 …… Internal exposed surface, 22 …… Thin film, 23 …… Shallow groove.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP 61-79769 (JP, A) JP 61-103530 (JP, A) JP 60-257512 (JP, A)

Claims (1)

[Claims] 1. A thin film forming apparatus for moving a substrate into a vacuum chamber and sequentially guiding the substrate to a plurality of independent processing chambers to perform a film forming process, wherein a plurality of the substrates are concentrically arranged and rotated. A pressure plate that has substantially the same diameter as the transfer plate and that hermetically press-bonds the transfer plate, a clip that holds the substrate at a predetermined position of the transfer plate, and a back surface of the substrate that is held at the predetermined position by the clip. Is a heater block provided on the side for preheating the substrate, having a gas flow passage for allowing a sputtering gas to flow therein, and heating the sputtering gas flowing in the gas flow passage to the substrate back surface. A heater block that is introduced into the processing chamber from an outlet provided so that The sputtering gas into plasma, the thin film forming apparatus characterized by applying to the target that includes a thin film forming mechanism depositing the particles flying from the target to the substrate.