JP2010150572A - Sputtering apparatus and method for manufacturing semiconductor device - Google Patents

Abstract

The present invention provides a sputtering apparatus and a semiconductor device manufacturing method capable of suppressing the breakage of an ion gauge and starting discharge stably.
A sputtering apparatus according to the present invention includes a chamber 2, a pipe 7 for evacuating the chamber, a gas line 13 for introducing a gas, a target 5, a stage base 3 for holding a wafer 4, and a target. A power supply for applying power, a current measuring device 9 for measuring a current flowing between the target and the stage base, an opening provided in the chamber, an ion gauge 12a connected to the opening, and the opening can be shielded. And a control mechanism 10 electrically connected to the shutter, an ion gauge and a current measuring device, and a control mechanism. Is characterized by controlling on / off of the switch and controlling the opening / closing operation of the shutter.
[Selection] Figure 1

Description

  The present invention relates to a sputtering apparatus and a method for manufacturing a semiconductor device, and more particularly to a sputtering apparatus and a method for manufacturing a semiconductor device, which can suppress breakage of an ion gauge and can start discharge stably.

  Conventionally, a sputtering apparatus used for manufacturing a semiconductor device has a vacuum chamber, and this vacuum chamber is evacuated by, for example, a dry pump to maintain the vacuum degree of the chamber. The degree of vacuum in the chamber is monitored by constantly measuring the vacuum pressure with an ion gauge installed in the chamber.

Next, the operation of the above-described vacuum chamber will be described.
First, the vacuum chamber is opened, and the wafer is carried into the vacuum chamber. Thereafter, the loaded wafer is set on a stage base and fixed by an electrostatic chuck or the like. In addition, the vacuum chamber opened for carrying the wafer is hermetically sealed, and evacuation is started by operating the dry pump.

  The vacuum chamber is evacuated by adjusting the pumping speed from the vacuum chamber to the dry pump and introducing argon gas into the vacuum chamber. The inside of the vacuum chamber is evacuated to a vacuum state of 1.5 Pa, for example. The pressure in the vacuum chamber is measured by an ion gauge that is connected to the vacuum chamber.

  After the inside of the vacuum chamber is maintained at a specified pressure, a voltage is applied to the target, whereby plasma discharge is started between the target and the wafer. The current flowing during plasma discharge is measured by a current measuring device, and film formation is performed on the wafer surface while monitoring the plasma discharge state.

  In the case of using a sputtering material that is difficult to start discharge and causes a delay in discharge, argon gas is introduced into the vacuum chamber to temporarily increase the pressure in the vacuum chamber, thereby facilitating the start of discharge. After the start of the discharge, the film forming process is performed by reducing the pressure to a specified pressure while maintaining the discharge. A similar technique is described in Patent Document 1, for example.

JP-A-8-74041 (0019-0024)

  As described above, by introducing argon gas as a gas trigger so as to temporarily increase the pressure in the vacuum chamber, discharge start is facilitated, and discharge is started between the target and the wafer.

  However, before starting discharge with argon gas by a gas trigger, primary electrons or secondary electrons generated from an ion gauge connected to the vacuum chamber may trigger the discharge. . As a result, the ion gauge may be damaged, and furthermore, discharge between the target and the wafer may fail. This makes it difficult to start stable discharge between the target and the wafer.

  The present invention has been made in consideration of the above-described circumstances, and an aspect according to the present invention is a manufacturing method of a sputtering apparatus and a semiconductor device capable of suppressing breakage of an ion gauge and starting discharge stably. Is the method.

In order to solve the above problems, a sputtering apparatus according to the present invention includes a chamber,
An exhaust mechanism for evacuating the chamber;
A gas introduction mechanism for introducing gas into the chamber;
A sputtering target disposed in the chamber;
A stage base for holding a film formation substrate disposed to face the sputtering target;
A power source for applying power to the sputtering target;
A current measuring mechanism for measuring a current flowing between the sputtering target and the stage base by applying the power to the sputtering target;
An opening provided in the chamber;
An ion gauge disposed in connection with the opening and measuring the pressure in the chamber;
A shutter disposed inside the chamber and provided to shield the opening;
A ground electrically connected to the shutter via a switch;
A control mechanism electrically connected to the shutter, the ion gauge and the current measurement mechanism;
Comprising
The control mechanism controls on / off of the switch and controls the opening / closing operation of the shutter.

  According to the sputtering apparatus, the opening is shielded by the shutter disposed inside the chamber. Thereby, it is possible to prevent the primary electron or secondary electron generated in the ion gauge from being discharged as a trigger. Therefore, it is possible to prevent the ion gauge from being damaged. As a result, discharge can be stably started between the sputtering target and the deposition target substrate.

  Further, in the sputtering apparatus according to the present invention, when the control mechanism detects that the inside of the chamber is at the first pressure by the ion gauge, the shutter is closed to shield the opening and the switch is turned on. Control is performed so that a ground potential is applied to the shutter in an on state, and the switch is turned off when it is detected by the ion gauge that the chamber is at a second pressure lower than the first pressure. The shutter is controlled so that the potential of the shutter is switched from the ground state to the floating state.

  Further, in the sputtering apparatus according to the present invention, when the control mechanism detects that the inside of the chamber is at the first pressure by the ion gauge, the shutter is closed to shield the opening and the switch is turned on. By controlling the ground potential to be applied to the shutter in the on state, and then applying power to the sputtering target by the power source, plasma discharge is started between the sputtering target and the deposition target substrate. When a current flows between the sputtering target and the deposition target substrate and this current is detected by the current measurement mechanism, the gas introduction mechanism and the exhaust mechanism are controlled so as to reduce the pressure in the chamber. Then, the inside of the chamber is made by the ion gauge. When detecting that a serial first lower than the pressure of the second pressure, and controls the switches a potential of the shutter is turned off so as to switch from the ground state to a floating state.

  The sputtering apparatus according to the present invention may further include a metal mesh disposed in the opening, and the metal mesh may be electrically connected to the ground via the switch.

  In the sputtering apparatus according to the present invention, when the control mechanism detects that the inside pressure of the chamber has become the first pressure by the ion gauge, the shutter is closed to shield the opening and the switch is turned on. When the state is controlled so that a ground potential is applied to the metal mesh and the shutter, and the ion gauge detects that the chamber is at a second pressure lower than the first pressure, the switch It is also possible to control so that the potential of the metal mesh and the shutter is switched from the ground state to the floating state by turning off the switch.

A method of manufacturing a semiconductor device according to the present invention includes a step of forming a film on a deposition target substrate using a sputtering apparatus.
The sputtering apparatus includes:
A chamber;
An exhaust mechanism for evacuating the chamber;
A gas introduction mechanism for introducing gas into the chamber;
A sputtering target disposed in the chamber;
A stage base for holding a film formation substrate disposed to face the sputtering target;
A power source for applying power to the sputtering target;
A current measuring mechanism for measuring a current flowing between the sputtering target and the stage base by applying the power to the sputtering target;
An opening provided in the chamber;
An ion gauge disposed in connection with the opening and measuring the pressure in the chamber;
A shutter disposed inside the chamber and provided to shield the opening;
A ground electrically connected to the shutter via a switch;
A control mechanism electrically connected to the shutter, the ion gauge and the current measurement mechanism;
Comprising
The control mechanism controls on / off of the switch and controls the opening / closing operation of the shutter.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The figure shown in FIG. 1 is a figure which shows typically the sputtering device which concerns on the 1st Embodiment of this invention.

  A sputtering apparatus 1 shown in FIG. 1 has a wafer standby chamber (not shown) connected to a vacuum chamber 2, and the wafer standby chamber (not shown) alternately performs evacuation and release to the atmosphere. The wafer is carried in and out. Therefore, when the sputtering apparatus 1 is continuously operated, the wafer can be loaded and unloaded without opening the vacuum chamber 2 to the atmosphere.

  A target 5 attached to a backing plate 6 is disposed in the upper part of the vacuum chamber 2. A stage base 3 is disposed in the lower part of the vacuum chamber 2 and directly below the target, and the stage base 3 is for placing the wafer 4 thereon. The vacuum chamber 2 is provided with a pipe 7 connected to a dry pump (not shown), and the pipe 7 is evacuated in a direction indicated by an arrow. An ion gauge 12a for measuring the pressure in the chamber is attached to the vacuum chamber 2 in connection with the chamber.

  In addition, a shutter 11b is installed around the opening of the ion gauge 12a, which is a connection point between the ion gauge 12a and the chamber 2, and the shutter 11b is opened and closed by the shutter shaft 11a. The shutter 11b and the shutter shaft 11a are made of, for example, metal. The shutter 11b and the shutter shaft 11a are electrically connected to the control mechanism 10, and the control mechanism 10 controls the opening / closing operation of the shutter 11b.

  The control mechanism 10 is electrically connected to one end of the changeover switch 8, and the other end of the changeover switch 8 is electrically connected to the ground. This ground is to apply a ground potential to the shutter 11b and the shutter shaft 11a through the switch 8 and the control mechanism 10. The switch 8 for switching is controlled by the control mechanism 10, and the shutter 11b and the shutter shaft 11a can be in an electrically floating state when the switch 8 for switching is opened (the state shown in FIG. 1).

  Further, the control mechanism 10 is electrically connected to the ion gauge 12a through a wiring, and a signal indicating the measurement result of the ion gauge 12a is sent to the control mechanism 10. Further, the control mechanism 10 is electrically connected to the current measuring device 9 through a wiring, and a signal indicating the measurement result of the current measuring device 9 is sent to the control mechanism 10.

  The target 5 is electrically connected to a DC power source 15 via a backing plate 6 and wiring, and this DC power source 15 is electrically connected to the wafer 4 via wiring and the stage base 3. The wafer 4 is electrically connected to the ground via the stage base 3 and wiring. Further, the current flowing between the wafer 4 and the target 5 during plasma discharge is measured by a current measuring device 9. Further, a gas line 13 is installed in the vacuum chamber 2, and argon gas is introduced into the vacuum chamber 2 through the gas line 13.

  Next, the operation of the above-described sputtering apparatus will be described with reference to the flowchart shown in FIG. FIG. 4 is a flowchart showing the operation sequence of the shutter 11b.

  First, the wafer 4 to be processed is carried into the vacuum chamber 2. The loaded wafer 4 is set on the stage table 3 and fixed to the stage table 3 by, for example, an electrostatic chuck or the like. Further, after the wafer 4 is carried in, the dry pump is operated to start evacuation. The pressure in the vacuum chamber 2 is constantly measured and monitored by the ion gauge 12a.

  Next, argon gas is introduced into the vacuum chamber 2 through the gas line 13 (S1). Next, in order to facilitate the start of discharge, the pressure in the vacuum chamber 2 is temporarily increased, and when the ion gauge 12a detects that the pressure in the vacuum chamber 2 has reached 1.5 Pa (S2), 1 The control mechanism 10 receives a signal that a pressure of 5 Pa has been detected. Then, the shutter shaft 11a is moved by the control mechanism 10 to close the shutter 11b, the periphery of the opening of the ion gauge 12a is shielded by the shutter 11b, the switching switch 8 is turned on by the control mechanism 10, and the ground potential is set to the shutter. 11b and the shutter shaft 11a (S3).

  In this way, the shutter 11b shields the periphery of the opening of the ion gauge 12a, and the shutter 11b is connected to the ground, whereby the shutter 11b blocks the primary or secondary electrons generated in the ion gauge 12a. Yes. This prepares for the start of discharge.

  Next, a voltage is applied between the target 5 and the wafer 4 by the DC power source 15 (S4). Next, plasma discharge is started between the target 5 and the wafer 4, and a current flows between the target 5 and the wafer 4, and this current is detected by the current measuring device 9 (S5). Next, the flow rate and exhaust of the argon gas are controlled so that the pressure in the vacuum chamber 2 that has been primarily increased is reduced to, for example, 1.0 Pa or less. Next, when the ion gauge 12a detects that the pressure in the vacuum chamber 2 is 1.0 Pa or less (S6), the control mechanism 10 receives a signal that the pressure of 1.0 Pa or less is detected. Then, the control mechanism 10 moves the shutter shaft 11a to open the shutter 11b, and the shutter 11b opens the opening of the ion gauge 12a. The potential of 11a is switched from the ground state to the floating state (S7).

  Next, sputtering on the wafer 4 is continued, and a film forming process for a predetermined time is performed. Thereafter, the wafer is unloaded from the vacuum chamber 2 and replaced with the next wafer waiting in the wafer standby chamber.

  As described above, according to the first embodiment of the present invention, before the start of discharge, the periphery of the opening of the ion gauge 12a is shielded by the shutter 11b, and primary electrons or secondary electrons generated by the ion gauge 12a are blocked by the shutter 11b. It is shut off. After confirming that discharge has started between the target and the wafer, the shutter 11b is opened to open the periphery of the opening of the ion gauge 12a. Thereby, it can prevent discharging using the primary electron or secondary electron which generate | occur | produces in the ion gauge 12a as a trigger. Therefore, it is possible to prevent the ion gauge from being damaged. As a result, discharge can be started stably between the target and the wafer.

  FIG. 2 is a diagram schematically showing a sputtering apparatus according to the second embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and only different parts will be described.

  A metal mesh 12a is attached to an opening of the ion gauge 12a, which is a connection point between the ion gauge 12a and the chamber. In the present embodiment, the shutter 11b and the shutter shaft 11a shown in FIG. 1 are not attached.

  Further, the metal mesh 12 b is electrically connected to the control mechanism 10. The control mechanism 10 is electrically connected to one end of the changeover switch 8, and the other end of the changeover switch 8 is electrically connected to the ground. This grounding applies a grounding potential to the metal mesh 12b through the switch 8 for switching and the control mechanism 10. The switch 8 for switching is controlled by the control mechanism 10, and the metal mesh 12b can be brought into an electrically floating state when the switch 8 for switching is opened (the state shown in FIG. 2).

  Next, regarding the operation of the sputtering apparatus shown in FIG. 2, a different part from the sputtering apparatus shown in FIG. 1 will be described.

  When it is detected by the ion gauge 12a that the pressure in the vacuum chamber 2 has become 1.5 Pa (S2) and the control mechanism 10 receives a signal that the pressure of 1.5 Pa has been detected, the control mechanism 10 switches the switch for switching. 8 is turned on, and a ground potential is applied to the metal mesh 12b (corresponding to S3).

  Thus, by covering the opening of the ion gauge 12a with the metal mesh 12b and further connecting the metal mesh 12b to the ground, the metal mesh 12b blocks the primary electrons or secondary electrons generated in the ion gauge 12a. ing. This prepares for the start of discharge.

  Further, when the pressure in the vacuum chamber 2 is detected by the ion gauge 12a (S6) and the control mechanism 10 receives a signal that the pressure of 1.0 Pa or less is detected, the control mechanism 10 The switching switch 8 is turned off, and the potential of the metal mesh 12b is switched from the ground state to the floating state (corresponding to S7).

  As described above, according to the second embodiment of the present invention, by covering the opening of the ion gauge 12a with the metal mesh 12b, primary electrons or secondary electrons generated in the ion gauge 12a are blocked by the metal mesh. . Therefore, it is possible to prevent discharge using primary electrons or secondary electrons generated in the ion gauge 12a as a trigger, and it is possible to prevent damage to the ion gauge. As a result, stable discharge start between the target and the wafer can be performed.

  FIG. 3 is a diagram schematically showing a sputtering apparatus according to the third embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and only different parts will be described.

  As shown in FIG. 3, a metal mesh 12 b is attached to an opening of the ion gauge 12 a that is a connection point between the ion gauge 12 a and the vacuum chamber 2. That is, this embodiment is a combination of the first embodiment and the second embodiment.

  Further, the metal mesh 12 b is electrically connected to the control mechanism 10. The ground is for applying a ground potential to the metal mesh 12b, the shutter 11b, and the shutter shaft 11a through the changeover switch 8 and the control mechanism 10.

  Next, regarding the operation of the sputtering apparatus shown in FIG. 3, a different part from the sputtering apparatus shown in FIG. 1 will be described.

  When it is detected by the ion gauge 12a that the pressure in the vacuum chamber 2 has become 1.5 Pa (S2) and the control mechanism 10 receives a signal that the pressure of 1.5 Pa has been detected, the control mechanism 10 switches the switch for switching. 8 is turned on, and a ground potential is applied to the metal mesh 12b, the shutter 11b, and the shutter shaft 11a (corresponding to S3).

  By shielding the periphery of the opening of the ion gauge 12a with the metal mesh 12b and the shutter 11b, and further connecting the shutter shaft 11a, the shutter 11b and the metal mesh 12b to the ground, primary electrons or secondary generated in the ion gauge 12a The shutter 11b and the metal mesh 12b block the electrons. This prepares for the start of discharge.

  Further, when the pressure in the vacuum chamber 2 is detected by the ion gauge 12a (S6) and the control mechanism 10 receives a signal that the pressure of 1.0 Pa or less is detected, the control mechanism 10 The switching switch 8 is turned off, and the potentials of the metal mesh 12b, the shutter 11b, and the shutter shaft 11a are switched from the ground state to the floating state (corresponding to S7).

  As described above, also in the third embodiment of the present invention, the same effect as that of the first embodiment can be obtained.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. In the above-described embodiments, the sputtering apparatus has been described. However, the present invention can be applied to other vacuum film forming apparatuses.

  Further, a method for manufacturing a semiconductor device including a step of forming a thin film on a wafer using the sputtering apparatus according to any of the first to third embodiments is also included in the scope of the present invention.

The figure which shows typically the sputtering device which concerns on the 1st Embodiment of this invention. The figure which shows typically the sputtering device which concerns on the 2nd Embodiment of this invention. The figure which shows typically the sputtering device which concerns on the 3rd Embodiment of this invention. 5 is a flowchart showing an operation sequence of the shutter according to the first embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Sputtering device, 2 ... Vacuum chamber, 3 ... Stage stand, 4 ... Wafer, 5 ... Target, 6 ... Backing plate, 7 ... Piping, 8 ... Switch, 9 ... Current measuring instrument, 10 ... Control mechanism, 11a ... Shutter shaft, 11b ... Shutter, 12a ... Ion gauge, 12b ... Metal mesh, 13 ... Gas line 15 DC power supply

Claims (6)

A chamber;
An exhaust mechanism for evacuating the chamber;
A gas introduction mechanism for introducing gas into the chamber;
A sputtering target disposed in the chamber;
A stage base for holding a film formation substrate disposed to face the sputtering target;
A power source for applying power to the sputtering target;
A current measuring mechanism for measuring a current flowing between the sputtering target and the stage base by applying the power to the sputtering target;
An opening provided in the chamber;
An ion gauge disposed in connection with the opening and measuring the pressure in the chamber;
A shutter disposed inside the chamber and provided to shield the opening;
A ground electrically connected to the shutter via a switch;
A control mechanism electrically connected to the shutter, the ion gauge and the current measurement mechanism;
Comprising
The said control mechanism controls ON / OFF of the said switch, and controls the opening / closing operation | movement of the said shutter, The sputtering device characterized by the above-mentioned.   2. The control mechanism according to claim 1, wherein when the ion gauge detects that the inside of the chamber has reached a first pressure, the control mechanism closes the shutter to shield the opening and sets the switch to an on state to establish a ground potential. Is applied to the shutter, and when the ion gauge detects that the chamber is at a second pressure lower than the first pressure, the switch is turned off to set the potential of the shutter. Is controlled so as to be switched from the ground state to the floating state.   2. The control mechanism according to claim 1, wherein when the ion gauge detects that the inside of the chamber has reached a first pressure, the control mechanism closes the shutter to shield the opening and sets the switch to an on state to establish a ground potential. Is applied to the shutter, and then, by applying power to the sputtering target by the power source, plasma discharge is started between the sputtering target and the deposition target substrate, When a current flows between the deposition target substrate and the current is detected by the current measurement mechanism, the gas introduction mechanism and the exhaust mechanism are controlled so as to reduce the pressure in the chamber, and then the ion A second pressure in the chamber lower than the first pressure by a gauge. When detecting that a force, sputtering and wherein the controller controls the switches a potential of the shutter is turned off so as to switch from the ground state to a floating state.   The sputtering apparatus according to claim 1, further comprising a metal mesh disposed in the opening, and the metal mesh is electrically connected to the ground via the switch.   5. The control mechanism according to claim 4, wherein when the ion gauge detects that the inside of the chamber has become the first pressure by the ion gauge, the shutter is closed to shield the opening and the switch is turned on to set the ground potential. When the ion gauge detects that the inside of the chamber has become a second pressure lower than the first pressure, the switch is turned off and the switch is turned off. A sputtering apparatus, wherein the potential of the metal mesh and the shutter is controlled to be switched from a ground state to a floating state. In a manufacturing method of a semiconductor device including a step of forming a film on a deposition target substrate using a sputtering apparatus,
The sputtering apparatus includes:
A chamber;
An exhaust mechanism for evacuating the chamber;
A gas introduction mechanism for introducing gas into the chamber;
A sputtering target disposed in the chamber;
A stage base for holding a film formation substrate disposed to face the sputtering target;
A power source for applying power to the sputtering target;
A current measuring mechanism for measuring a current flowing between the sputtering target and the stage base by applying the power to the sputtering target;
An opening provided in the chamber;
An ion gauge disposed in connection with the opening and measuring the pressure in the chamber;
A shutter disposed inside the chamber and provided to shield the opening;
A ground electrically connected to the shutter via a switch;
A control mechanism electrically connected to the shutter, the ion gauge and the current measurement mechanism;
Comprising
The method of manufacturing a semiconductor device, wherein the control mechanism controls on / off of the switch and controls the opening / closing operation of the shutter.

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