JPH08260153A - Induction coupling plasma cvd apparatus - Google Patents

Abstract

PURPOSE: To provide an induction coupling plasma CVD apparatus capable of preventing the adhesion of the intermediate products generated during film formation on a surface to be formed with films. CONSTITUTION: Plasma 83 is generated on the inner side of a chamber 5 of a dielectric window 53 disposed in contact with an annular antenna 69 when a high-frequency is impressed on this antenna 69. The chamber 5 is evacuated from a discharge pipe 11 to a vacuum state and a stage 25 disposed therein heats a work 13. Gas supplying devices 35, 63 supply at least two kinds of reactive gases into the chamber 5. The dielectric window 53 is disposed on the rear surface of the chamber 5 and the antenna 69 is disposed on the rear surface of the dielectric window 53 and, therefore, the plasma 83 is generated in the lower part of the chamber 5. The stage 25 is disposed above the dielectric window 53 and a work retainer 27 fixes the work 13 which is held in contact with the rear surface of the stage 25.

Description

Detailed Description of the Invention

[0001]

This invention relates to an inductively coupled plasma CV.
D device, more specifically, inductively coupled plasma (ICP) C with less contamination by intermediate products
It relates to a VD device.

[0002]

2. Description of the Related Art FIG. 2 shows a so-called inductively coupled plasma CV.
The D device 101 is shown, and a case of forming a SiO2 film will be described as an example.

In FIG. 2, a quartz ring 105 is provided inside the chamber 103 having a double structure for cooling, and an upper lid 107 is provided above the chamber 103.
Further, lower lids 109 are provided on the lower side and sealed by O-rings 111 and the like.

On the upper surface of the upper lid 107 of the chamber 103,
A dielectric window 113 for high-frequency radio waves made of quartz is provided, and two terminals 115,
A copper ring antenna 119 having 117 is provided. In addition to quartz, the dielectric window 113 may be made of a material such as alumina that transmits radio waves but does not transmit infrared rays. Further, a matching box 121 is connected to the terminals 115 and 117, and a high frequency power source 123 is further connected.

Although the ring-shaped antenna 119 is not cooled here, it is in the range of several tens depending on the supplied high frequency.
Considering that the temperature rises to 0 ° C, antenna 1
It is also conceivable that 19 is tubular and the cooling water is flowed.

An O-ring 125 is provided between the dielectric window 113 and the upper lid 107 to seal the internal space of the chamber 103. In order to cool the O-ring 125, the upper lid 107 is provided with a channel 127 for cooling water, and the cooling water is injected from the inlet 129 and drained from the drain 131.

Further, the upper lid 107 is provided with a pipe 133 for supplying oxygen (O ₂ ) gas, and a supply path 135 connected to this pipe 133 is provided. This supply path 13
A gas supply hole 137 is provided at the tip of No. 5, and oxygen (O ₂ ) is supplied from this gas supply hole 137 to the vicinity of the dielectric window 113.
Supplying gas.

On the other hand, a plurality of lower columns 139 are erected on the lower lid 109 of the chamber 103.
A heater support plate 141 is provided on the upper side of 39.
A plurality of upper support columns 14 are further provided on the heater support plate 141.
3 is provided.

On the upper column 143, several sets of reflectors 14 are provided.
5 is provided, and a heater 147 is provided inside the reflection plate 145. A wafer 149, which is a work, is placed on the heater 147 and uniformly heated to, for example, about 600 ° C. Therefore, the upper column 143 is made of a material having a small thermal conductivity such as ceramics.

A ring-shaped gas supply pipe 151 made of, for example, quartz is provided above the heater 147 to blow out gas toward the inside of the ring. A branch pipe 153 for supplying gas is attached to the gas supply pipe 151. The branch pipe 153 is connected to a SUS pipe 157 that penetrates the lower lid 109 of the chamber 103 by a union joint 155.

A cooling unit 159 is provided around the heater 147 and the reflector 145 on the upper surface of the heater support plate 141 to shield the heat flow from the heater 147 to the reflector 145. Further, an exhaust pipe 161 is provided in the lower lid 109, and the chamber 1
The inside of 03 is exhausted.

Next, the above-mentioned inductively coupled plasma (ICP)
The operation of the CVD apparatus 101 will be described. First, the wafer 149 is placed on the heater 147 in the chamber 103 by a loader (not shown). If the pressure in the chamber 103 is atmospheric pressure, the exhaust pipe 16
Evacuate from 1 to, for example, a vacuum of 10 ⁻⁶ to 10 ⁻⁷ Torr.

An electric current is supplied to the heater 147 so that the temperature becomes 300 °.
Heat to about C to 500 ° C. At this time, cooling water is allowed to flow in all the cooling sections. After the temperature is raised to an appropriate temperature, oxygen (O ₂ ) gas is supplied from the gas supply hole 137,
Dichlorosilane (SiH ₂ Cl ₂ ) gas is supplied from the gas supply pipe 151 at a predetermined ratio.

After the pressure inside the chamber 103 is adjusted to a predetermined pressure by a throttle valve or the like (not shown), high frequency power is supplied to the terminals 115 and 117 via the matching box 121.
From the antenna 119. As a result, plasma 163 is formed immediately below the dielectric window 113. Then, the plasma 163 decomposes and synthesizes the oxygen (O ₂ ) gas and the dichlorosilane (SiH ₂ Cl ₂ ) gas previously supplied, and the SiO ₂ film is deposited on the wafer 149. The deposited film thickness may be confirmed in-situ (in-situ) or may be controlled by time. When the film formation is completed, the supply of oxygen gas and dichlorosilane gas is stopped and the high frequency power source 12
3 is turned off, the exhaust pipe 161 exhausts, and the process ends.

[0015]

However, in such a conventional technique, when a gas such as dichlorosilane is used, a large amount of powdery intermediate products which are considered to be chlorides are generated, As a result of the product adhering to the film formation surface of the wafer 149, there is a problem that a film is not formed only on the adhered part and a recess is formed to cause a defect.

Since the number of defects increases as the film thickness of the film to be formed increases, it becomes a very serious problem when a thick film is deposited.

The object of the present invention has been made by paying attention to the above-mentioned conventional techniques, and inductive coupling capable of preventing an intermediate product generated during film formation from adhering to a film formation surface. It is to provide a plasma CVD apparatus.

[0018]

In order to achieve the above object, the inductively coupled plasma CVD apparatus of the present invention according to claim 1 is provided with a ring-shaped antenna capable of applying high frequency and in contact with this antenna. A dielectric window, and a chamber provided with the dielectric window and capable of maintaining airtightness;
A stage provided inside the chamber for heating a work; an exhaust device for exhausting the interior of the chamber; and a gas supply device capable of supplying at least two kinds of reaction gases in desired amounts to the chamber. An inductively coupled plasma CVD apparatus provided with the dielectric window provided on the lower surface of the chamber, the antenna arranged below the dielectric window, and the stage provided above the dielectric window. It is characterized in that a work retainer is provided in contact with the lower surface of the stage to mount the work.

According to a second aspect of the present invention, there is provided an inductively coupled plasma CVD apparatus according to the first aspect of the present invention, wherein one gas supply pipe of the gas supply apparatus has a ring shape and is provided near the lower side of the stage, and the other gas is supplied. It is characterized in that the supply pipe is provided close to the inside of the chamber of the dielectric window.

Further, the inductively coupled plasma CVD apparatus according to the present invention according to claim 3 is characterized by comprising moving means for moving one of the gas supply pipes according to claim 2 up and down with respect to the stage. is there.

[0021]

In the inductively coupled plasma CVD apparatus according to the first aspect, when a high frequency is applied to the ring-shaped antenna, plasma is generated inside the chamber of the dielectric window provided in contact with the antenna. The chamber can be evacuated by an exhaust device to be in a vacuum state, and a stage provided inside the chamber heats the work. A gas supply device supplies at least two kinds of reaction gases in desired amounts into the chamber. At this time, since the dielectric window is provided on the lower surface of the chamber and the antenna is arranged on the lower side of the dielectric window, plasma is generated in the lower part of the chamber when the antenna is applied with a high frequency. Further, the stage is provided above the dielectric window, and the work retainer fixes the work in contact with the lower surface of the stage to deposit a film on the lower surface of the work.

In the inductively coupled plasma CVD apparatus according to a second aspect, one of the ring-shaped gas supply pipes provided near the lower side of the stage in the gas supply apparatus according to the first aspect is located below the stage. Supply gas from the side. Further, in the gas supply device according to claim 1, the other gas supply pipe provided close to the inside of the chamber of the dielectric window supplies gas toward the plasma generated in the lower portion of the chamber. .

The inductively coupled plasma CV according to claim 3
In the D device, one of the gas supply pipes according to claim 2 moves up and down with respect to the stage by the moving means.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an inductively coupled plasma CVD apparatus 1 according to the present invention. In FIG. 1, an inductively coupled plasma CVD apparatus 1 is provided on a pedestal 3. That is, the chamber 5 having a double structure for flowing the cooling water is provided with the upper lid 7 and the lower lid 9 in a state where each of them is kept sealed, and the lower lid 9 is provided on the pedestal 3. There is. Further, on the side surface of the chamber 5, an exhaust pipe 11 for exhausting the inside of the chamber 5 and a wafer 1 as a work are provided.
A port 15 for loading / unloading 3 is provided.

A cylinder 17 as a vertically moving means is provided on the upper surface of the upper lid 7, and a piston rod 19 thereof is provided.
Can be moved up and down. An elevating plate 21 is attached to the upper end of the piston rod 19, and the elevating plate 2
A plurality of support rods 23 extending through the upper lid 7 and extending inside the chamber 5 are attached to the unit 1. Therefore, the operation of the cylinder 17 causes the support rod 23 to move up and down while maintaining the sealed state of the chamber 5.

A sample stage 25 as a stage having a built-in heater is attached to the lower end of the support rod 23.
The wafer 13 is fixed to the lower surface of the sample table 25 by a wafer retainer 27 as a workpiece retainer in a state in which the wafer 13 is in close contact. That is, the wafer 13 is fixed with the film formation surface facing down. Therefore, the upper surface of the wafer 13 is heated to about 300 ° C. by the heater of the sample table 25.

A plurality of sets of reflectors 29 surrounding the sample table 25 are attached to the lower surface of the upper lid 7 above the sample table 25 by a plurality of columns 31 made of a material such as ceramics having a low thermal conductivity. There is. Further, a cooling unit 33 is provided around the reflection plate 29.

A ring-shaped quartz gas supply pipe 35 is attached to the lower side of the wafer retainer 27 by a gas pipe bracket 37. The gas supply pipe 35 is provided with a large number of nozzles (not shown), and the wafer 13
Dichlorosilane gas is spouted toward.

A branch pipe 39 is connected to the gas supply pipe 35, and an O-ring seal type union joint 41 is provided on the branch pipe 39. An expandable flexible tube 45 is provided around the branch pipe 39 between the union joint 41 and the welded joint 43 provided on the upper lid 7, and the flexible tube 45 is provided when the branch pipe 39 moves up and down. 5 Maintains airtightness inside. The pipe 47 protruding upward from the upper lid 7 of the branch pipe 39 has a valve 4
9 is provided to turn on / off the gas supply.

Since the cylinder 17 is driven as described above and the piston rod 19 is moved up and down, the sample stage 25, the gas supply pipe 35, the branch pipe 39 and the wafer 13 are moved up and down as a unit. And flexible tube 4
5 will expand and contract.

On the other hand, the lower lid 9 of the chamber 5 attached to the upper surface of the pedestal 3 is provided with an opening 51 at the center, and a dielectric window 53 is attached to cover the opening 51 from below. ing. The dielectric window 53 keeps the chamber 5 sealed by an O-ring seal 55. Since the heat-resistant temperature of the O-ring seal 55 is about 200 ° C. and cannot withstand high temperature, the flow path 57 is provided inside the lower lid 9, and the cooling water is injected from the water supply port 59 to drain the water.
It is cooled by discharging from 1. Also, the lower lid 9
Is provided with an oxygen gas supply pipe 63 and a gas supply path 65, and oxygen gas is supplied from the supply hole 67 into the chamber 5.

A ring-shaped antenna 69 is provided in close contact with the lower surface of the dielectric window 53. The antenna 69 is provided with terminals 71 and 73 for supplying high frequency so as to face downward.

Below the lower lid 9, a bracket 77 is hung by a supporting member 75 such as a channel provided on the frame 3 supporting the chamber 5. A matching box 79 is provided on the bracket 77, and terminals 71, 73 provided on the lower lid 9 are provided.
Connected with. Also, this matching box 79
Is connected to a high frequency power supply 81.

Next, the inductively coupled plasma CV described above
The operation of the D device 1 will be described.

First, the wafer 13 is loaded from the port 15 into the chamber 5 by a robot hand (not shown) or the like. At this time, the wafer retainer 27, the gas supply pipe 35, and the like are at the lowest position by the cylinder 17, and the wafer 13 is placed on the wafer retainer 27.

After confirming that the wafer 13 is placed on the wafer retainer 27 by a sensor (not shown) or the like, the cylinder 17
Thus, the wafer 13, the gas supply pipe 35, etc. are raised. As a result, the flexible tube 45 contracts. Then, when the wafer 13 comes into contact with the lower surface of the sample table 25 (the state of FIG. 1), the driving of the cylinder 17 is stopped.

When the chamber 5 is not equipped with a load lock mechanism, the inside of the chamber 5 is at atmospheric pressure, so that the exhaust pipe 11 is evacuated to 10 ^-6 to 10 ^-7 Torr. When the load lock mechanism is provided, the exhaust step is not necessary. When a predetermined degree of vacuum is reached, the heater built in the sample table 25 is turned on and the sample table 25 is heated to 300 ° C.
Heat to a degree. At this time, the chamber 5 is cooled by the cooling water.
Etc. are cooling.

Next, oxygen gas is supplied through the oxygen gas supply pipe 63, and the oxygen gas is blown into the chamber 5 through the supply hole 67. On the other hand, the valve 49 is opened to supply the dichlorosilane gas to the gas supply pipe 35, and the dichlorosilane gas is blown from the many nozzles of the gas supply pipe 35 toward the lower surface of the wafer 13 which is the film formation surface.

After that, the high frequency power supply 81 is turned on, and the high frequency power is supplied to the antenna 69 through the matching box 79.
Supply to The high frequency radio wave is transmitted to the inside of the chamber 5 through the dielectric window 53 and forms the inductively coupled plasma 83. Dichlorosilane gas and oxygen gas are decomposed and synthesized by the plasma 83, and SiO ₂ is deposited on the lower surface of the wafer 13.
Deposit the film.

The film thickness may be confirmed in-situ or may be controlled by time. When the film formation to the target film thickness is completed, the gas supply is stopped, the high frequency power supply 81 is turned off, and the chamber 5 is evacuated to a vacuum degree of 10 ⁻⁶ to 10 ⁻⁷ Torr. Then, when there is no load lock mechanism, the chamber 5 is opened to the atmosphere.

When the predetermined pressure is reached, the wafer retainer 27, the gas supply pipe 35, etc. are lowered by the cylinder 17, and the wafer 13 formed by the robot hand (not shown) is taken out from the chamber 5 to complete the process.

Such an inductively coupled plasma CVD apparatus 1
According to, the intermediate product detected after the film formation of 10 μm is 2
It was found that the number was 0 pieces / cm ² , which was significantly reduced compared to 80 pieces / cm ² when the film was formed under the same conditions in the conventional plasma CVD apparatus. As a result, high quality film formation can be performed.

The present invention is not limited to the above-described embodiments, but can be implemented in other modes by making appropriate changes. In the above-described embodiment, the oxygen gas is supplied from the supply hole 67, and the gas supply pipe 3
The case of supplying the dichlorosilane gas from No. 5 has been described, but these are variously changed depending on the object of film formation and the like.

[0045]

As described above, in the inductively coupled plasma CVD apparatus according to the first aspect of the present invention, the dielectric window is provided on the lower surface of the chamber and the antenna is arranged below the dielectric window. Therefore, when a high frequency is applied to the antenna, plasma is generated in the lower part of the chamber. Further, since the stage is provided above the dielectric window and the work retainer fixes the work in contact with the lower surface of the stage, at least two kinds of gas supplied from the gas supply device are decomposed. -Synthesize and deposit a film on the lower surface of the work from below. For this reason, since the intermediate product generated during the decomposition / synthesis of the gas hardly adheres to the lower surface of the work, it is possible to form a high-quality film containing little intermediate product.

In the inductively coupled plasma CVD apparatus according to a second aspect, one of the ring-shaped gas supply pipes provided near the lower side of the stage in the gas supply apparatus according to the first aspect is located below the stage. While supplying gas from the side, since the other gas supply pipe provided near the inside of the chamber of the dielectric window of the gas supply device supplies gas toward the plasma generated in the lower part of the chamber, Gas is efficiently decomposed and synthesized below the work. Therefore, the film can be easily deposited on the lower surface of the work.

An inductively coupled plasma CV according to claim 3
In the apparatus D, one of the gas supply pipes according to claim 2, that is, the gas supply pipe provided near the lower side of the stage moves up and down with respect to the stage by the moving means. The work after film formation can be easily carried out.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of an inductively coupled plasma CVD apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing a conventional inductively coupled plasma CVD apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inductively coupled plasma CVD apparatus 5 Chamber 11 Exhaust pipe (exhaust device) 13 Wafer (workpiece) 17 Cylinder (moving means) 25 Sample stage (stage) 35 One gas supply pipe (gas supply device) 53 Dielectric window 63 The other Gas supply pipe (gas supply device) 69 Antenna

Claims (3)

[Claims] 1. A ring-shaped antenna to which a high frequency can be applied, a dielectric window provided in contact with the antenna, a chamber having the dielectric window and capable of maintaining airtightness, and inside the chamber. And a gas supply device capable of supplying a desired amount of at least two kinds of reaction gases to the chamber, and an exhaust device for exhausting the inside of the chamber. A plasma CVD apparatus, wherein the dielectric window is provided on a lower surface of the chamber, the antenna is arranged below the dielectric window, the stage is provided above the dielectric window, and the lower surface of the stage is provided. An inductively coupled plasma CVD apparatus characterized in that a work holder is provided so as to attach a work in contact therewith. 2. One of the gas supply pipes of the gas supply device has a ring shape and is provided near the lower side of the stage, and the other gas supply pipe is provided near the inside of the chamber of the dielectric window. Claim 1 characterized by the above.
The inductively coupled plasma CVD apparatus described. 3. The inductively coupled plasma CVD apparatus according to claim 2, further comprising moving means for moving the one gas supply pipe up and down with respect to the stage.