JP2001326269A - Semiconductor manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing apparatus which is little in deposition of particles to a semiconductor substrate and also in device damage. SOLUTION: A pusher pin is composed of a pin and a material covering around it, the material constituting the pin has a higher electric resistivity than that of the material covering around it and a top part of the pin directly contacting the semiconductor substrate is not covered but bared.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus provided with a substrate supporting device for holding a semiconductor substrate.

[0002]

2. Description of the Related Art At the present time, with the increasing integration of various semiconductor devices such as memories and microcomputer chips, miniaturization of integrated circuits is rapidly advancing. For example, at present, semiconductor devices having integrated circuits of the 0.25 μm rule to the 0.18 μm rule are mass-produced, and the importance of measures for preventing particle contamination on the surface of a semiconductor substrate such as a semiconductor wafer is increasing.

Conventionally, plasma C using reactive plasma has been used for processing a semiconductor substrate in a semiconductor device manufacturing process.
A VD (Chemical Vapor Deposition) apparatus, a plasma etching apparatus and the like are used. In these plasma processing apparatuses, an electrostatic suction apparatus is widely used. Hereinafter, the electrostatic attraction device will be described with reference to FIG. Electrostatic suction device 1
Is provided with two suction electrodes, an inner electrode 2 and an outer electrode 2 ′, and an insulating material 3 covering the electrodes 2 and 2 ′. ′, A predetermined DC voltage is applied thereto to generate an electrostatic force between them, and the semiconductor substrate 4 is attracted and held on the upper surface of the electrostatic attraction device 1.

As shown in Japanese Patent Application Laid-Open No. 11-233601, a pusher pin has conventionally been used for mounting a semiconductor substrate 4 on an electrostatic chuck 1. The electrostatic suction device 1 is provided with three or more holes 5, each of which has a pusher pin 6 penetrating therethrough. The pusher pin 6 is attached to the elevating part 7, and the pusher pin 6 is pushed up or down by moving the elevating part 7 up or down.
Thereby, the semiconductor substrate 4 is raised or lowered.

Conventionally, the pusher pin 6 has been made of a material having a large electric resistivity such as ceramics (for example, alumina (Al ₂ O ₃ )) or quartz (SiO ₂ ). This is because, if a material having a small electric resistivity such as a metal is used, when the back surface of the semiconductor substrate 4 comes into contact with the upper end of the pusher pin 6 when the pusher pin 6 is pushed up, the material is accumulated on the semiconductor substrate 4 by electrostatic attraction. This is because there is a danger that a circuit formed on the semiconductor substrate 4 will be destroyed (for example, dielectric breakdown) because the accumulated electric charge instantaneously flows to the ground via the pusher pin 6. This causes device damage in the manufacture of semiconductor devices and causes a reduction in yield. When the semiconductor device manufacturing process performed on the semiconductor substrate 4 is a plasma process, the electric charge accumulated in the semiconductor substrate 4 is further increased by the plasma, so that when the pusher pin 6 is pushed up, the back surface of the semiconductor substrate 4 and the upper end of the pusher pin 6 The risk of the circuit formed on the semiconductor substrate 4 being destroyed when the contact is made further increases. Therefore, by forming the pusher pin 6 from a material having a large electrical resistivity such as ceramics, the charge accumulated in the semiconductor substrate 4 when the back surface of the semiconductor substrate 4 is brought into contact with the upper end of the pusher pin 6 is gradually eliminated, and the semiconductor substrate 4 The destruction of the circuit formed in the above is prevented.

However, when the pusher pin 6 is made of a material having a large electric resistivity, another adverse effect appears. When the pusher pin 6 is pushed up or down, vibration occurs due to a problem or the like, and when friction occurs between the inner wall surface of the hole 5 provided in the electrostatic chuck 1 and the pusher pin 6, static electricity is generated. As a result, the semiconductor substrate 4 is charged, and particles floating near the surface of the semiconductor substrate 4 are attracted to and adhere to the semiconductor substrate 4 by static electricity. The attachment of particles to the semiconductor substrate 4 is not desirable because it causes a reduction in yield in the manufacture of semiconductor devices.

[0007]

In the above prior art, device damage can be prevented by forming the pusher pin 6 from a material having a large electrical resistivity such as ceramics or quartz. The problem of inducing particle adhesion occurs.

SUMMARY OF THE INVENTION The present invention has been made in order to avoid the above problems, and has as its object to prevent a device from being damaged and to provide a semiconductor manufacturing apparatus having a substrate support device that causes less adhesion of particles to the surface of a semiconductor substrate 4. It is to provide.

[0009]

According to the present invention, the surface of the pusher pin 6 made of a material having a large electric resistivity such as ceramics or quartz is coated with a material having a small electric resistivity such as a metal. At this time, the upper part of the pusher pin 6 which is in direct contact with the back surface of the semiconductor substrate is not covered with a material having a small electric resistivity such as a metal, but a material having a large electric resistivity such as a ceramic is exposed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS.

FIG. 1 shows a magnetic field microwave plasma CVD apparatus to which an embodiment of the present invention is applied. A quartz lid 9 is provided on the side wall 8, and the electrostatic chuck 1 is provided in a processing chamber 10 formed by the quartz lid 9, and the semiconductor substrate 4 is sucked thereon to perform processing. A microwave 12 generated by a microwave oscillator 11 is introduced by a waveguide 13 and the discharge tube 1
Plasma 16 is generated by interaction with a magnetic field induced by a coil 15 mounted around 4. The processing gas 17 is introduced into the processing chamber 10 through the nozzle 18. A process (here, a film formation process) is performed by exposing the semiconductor substrate 4 to the plasma 16. The processing gas 17 and the reaction products are exhausted from an exhaust port 19.

A pusher pin 6 is disposed so as to penetrate the entire electrostatic chuck 1 up and down, and is attached to a lifting unit 7. The pusher pin 6 is moved up and down by moving the elevating unit 7 up and down, and the semiconductor substrate 4 carried into the processing chamber 10 is placed on the upper surface of the electrostatic adsorption device 1 by using a transfer robot (not shown). I do. A bellows 20 is provided between the elevating unit 7 and the side wall 8 to keep the processing chamber 10 airtight.

FIG. 2 is a side sectional view of the electrostatic suction device 1 of the embodiment, and shows an enlarged view when the semiconductor substrate 4 is sucked.

Since the semiconductor substrate 4 is heated by the plasma 16, cooling is often required in order to maintain an appropriate temperature. Since normal plasma processing is performed under a low pressure of about several Pa, the heat transfer efficiency between the semiconductor substrate 4 and the upper surface of the electrostatic chuck 1 is low, and the cooling efficiency of the semiconductor substrate 4 is low. Thus, while adsorbing the semiconductor substrate 4 on the upper surface of the electrostatic adsorption device 1, a heat transfer gas such as helium (He) having a high thermal conductivity is supplied from the heat transfer gas supply pipe 21 between the two, and the pressure of the heat transfer gas is increased. Is controlled, thereby controlling the thermal conductance between the two. Although not shown here, the surface shape of the upper surface of the electrostatic adsorption device 1 is uneven, and the semiconductor substrate 4
The pressure of the heat transfer gas between the upper surface and the upper surface of the electrostatic attraction device 1 is devised to be uniform at the center and at the periphery.

Inside the electrostatic suction device 1, two suction electrodes, an inner suction electrode 2 and an outer suction electrode 2 ', are provided. A DC power supply 22 for applying a positive voltage to the suction electrode 2 on the inner peripheral side and the voltage application is turned on and off.
A switch 23 for performing FF is connected. Further, a DC power supply 22 'for applying a negative voltage and a switch 23' for turning ON / OFF the voltage application are connected to the outer side attracting electrode 2 '. By supplying power to these suction electrodes 2 and 2 ′, the semiconductor substrate 4 is suctioned and held on the upper surface of the electrostatic suction device 1.

A refrigerant flow path 24 is formed inside the electrostatic adsorption device 1, and a refrigerant supply port 25 is formed by a cooling device connected to the outside.
From the refrigerant outlet 24, through the refrigerant passage 24,
Then, the electrostatic suction device 1 is cooled by being discharged from the vacuum cleaner 6.
Heat received by the semiconductor substrate 4 during the plasma processing is released to the refrigerant flowing inside the refrigerant channel 24. Plasma 16
A cover 27 is attached to protect the electrostatic attraction device 1 from the pressure.

FIG. 3 is an enlarged side sectional view of the vicinity of the pusher pin 6 in the lifting mechanism for the pusher pin 6 of the electrostatic chuck 1 of the embodiment. In this embodiment, the pusher pin 6 is formed by covering a pin 29 made of alumina with a pipe 29 made of aluminum (Al). Also, pusher pin 6 is attached to jig 3
0, nuts 31 and bolts 32 are used to attach to the elevating section 7. The elevating unit 7 is electrically grounded. Thus, when the semiconductor substrate 4 comes into contact with the pusher pin 6, the electric charge accumulated in the semiconductor substrate 4 gradually flows to the ground via the pin 28. Further, since the pipe 29 has a small electric resistivity, even if friction occurs between the pipe 29 and the inner wall surface of the hole 5, the electric charge immediately flows to the ground via the pipe 29, and the pusher pin 6 is charged by static electricity. There is nothing.

Hereinafter, an actual semiconductor device manufacturing process using the electrostatic chuck 1 will be described in detail with reference to FIGS. 1, 2 and 3. Here, a plasma CVD process will be described as an example of a semiconductor device manufacturing process.

(1) The semiconductor substrate 4 before the plasma CVD process is carried into the processing chamber 10 by a transfer robot (not shown). At this time, the pusher pins 6 are pushed up by raising the elevating unit 7 to receive the semiconductor substrate 4 from the transfer robot, and then the pusher pins 6 are pushed down by lowering the elevating unit 7 so that the semiconductor substrate 4 is held by the electrostatic chuck 1. Place on top. At this time, even if friction occurs between the pusher pin 6 and the inner wall of the hole 5 provided in the electrostatic suction device 1, the pusher pin 6 is not charged by static electricity. Therefore, the semiconductor substrate 4 is not charged by static electricity, and does not attract particles near the surface of the semiconductor substrate 4.

(2) In the processing chamber 10, the semiconductor substrate 4 is subjected to a plasma CVD process.

(3) Before transferring the semiconductor substrate 4 after the plasma CVD process to the transfer robot, the lifting unit 7 is raised to push up the pusher pin 6. At this time, even if the semiconductor substrate 4 is charged by the electrostatic chuck or the plasma CVD process, the electric resistance of the pusher pin 6 is large, so that a large current that causes damage to a circuit formed on the semiconductor substrate 4 is generated. There is no instantaneous flow. Further, even if friction occurs between the pusher pin 6 and the inner wall of the hole 5 provided in the electrostatic chuck 1, the pusher pin 6 is not charged by static electricity. Therefore, the semiconductor substrate 4 is not charged by static electricity, and does not attract particles near the surface of the semiconductor substrate 4.

(4) The pusher pin 6 is pushed down by lowering the elevating unit 7, and the semiconductor substrate 4 after the plasma CVD process is delivered by the transfer robot. At this time, even if friction occurs between the pusher pin 6 and the inner wall of the hole 5 provided in the electrostatic suction device 1, the pusher pin 6 is not charged by static electricity. Therefore, the semiconductor substrate 4 is not charged by static electricity, and does not attract particles near the surface of the semiconductor substrate 4.

By repeating the above processes (1) to (4), a plurality of semiconductor substrates 4 can be continuously subjected to the plasma CVD process.

In this embodiment, the pin 28 constituting the pusher pin 6 is made of alumina, and the pipe 29 covering the pin 28
Is made of aluminum, but the material constituting each is not limited to them. What is important is that the pins 28 are made of a material having a large electrical resistivity in order to prevent device damage to the semiconductor substrate 4, and that friction occurs between the pusher pins 6 and the inner walls of the holes 5 provided in the electrostatic chuck 1. Even if the pin 28 is covered with a material having a small electric resistivity so as not to be charged by static electricity, the upper portion of the pusher pin 6 is not covered with a material having a small electric resistivity and is made of a material having a large electric resistivity. The exposed pin 28 is exposed.

Further, in this embodiment, the pipe 28 is covered to cover the pin 28 with a material having a small electric resistivity.
The means for coating is not limited to this. What is important is that the pin 28 is made of a material having a small electrical resistivity so that the pusher pin 6 is not charged by static electricity even if friction occurs between the pusher pin 6 and the inner wall of the hole 5 provided in the electrostatic chuck 1. For example, the pin 28 may be covered by forming a thin film of a material having a small electric resistivity on the pin 28 by means such as sputtering, CVD, plating, or coating.

In this embodiment, the semiconductor device manufacturing process is a plasma CVD process, and the substrate supporting device is an electrostatic attraction device. However, according to the present invention, the pins 28 are coated with a material having a small electric resistivity to thereby form the semiconductor substrate 4. Is prevented from being charged by static electricity, and is also effective for a semiconductor device manufacturing process other than the plasma CVD process and a semiconductor manufacturing device using a substrate supporting device other than the electrostatic chucking device.

[0027]

As described above, according to the present invention,
In a semiconductor manufacturing apparatus using a substrate supporting apparatus, it is possible to provide a high-yield semiconductor manufacturing apparatus with less adhesion of particles to the surface of a semiconductor substrate while preventing device damage.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a magnetic field microwave plasma CVD apparatus showing an embodiment of the present invention.

FIG. 2 is an enlarged side view of an electrostatic chuck used in a magnetic field microwave plasma CVD apparatus according to an embodiment of the present invention.

FIG. 3 is an enlarged side sectional view of a lifting mechanism for a pusher pin 6 in an electrostatic chuck used in a magnetic field microwave plasma CVD apparatus according to an embodiment of the present invention.

FIG. 4 is a side sectional view showing a conventional example of an electrostatic suction device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electrostatic adsorption device, 4 ... Semiconductor substrate, 6 ... Pusher pin, 7 ... Elevating part, 8 ... Side wall, 9 ... Quartz lid, 10 ... Processing chamber, 11 ... Microwave oscillator, 12 ... Microwave, 13
... Waveguide, 14 discharge tube, 15 coil, 16 plasma, 17 processing gas, 18 nozzle, 19 exhaust port.

Continued on the front page (72) Inventor Katsumi Oyama 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture F-term in Kokubu Works, Hitachi, Ltd. (Reference) 4K030 CA04 CA12 FA02 GA12 KA46 KA47 5F004 AA06 AA14 BB18 BC08 5F031 CA02 HA02 HA16 HA33 MA28 PA21 5F045 BB15 BB16 DP02 DQ10 EM05 EM10

Claims (1)

[Claims] 1. A semiconductor manufacturing apparatus comprising a substrate support device, a mechanism for moving a semiconductor substrate up and down using a pusher pin, and carrying the semiconductor substrate into and out of the processing chamber. The material of the pin is made of a material having a higher electrical resistivity than the material of the material surrounding the pin, and the pin upper portion that is in direct contact with the semiconductor substrate is exposed without being covered. A semiconductor manufacturing apparatus comprising a pusher pin characterized by the above-mentioned.