JP2005268689A - Substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing apparatus having a function capable of sensing the secular change of a heating wire with high reliability. <P>SOLUTION: The substrate processing apparatus provides a heating means for heating the interior of a processing chamber 202 and supplies a secular change sensing power PD of frequency higher than that of heating power to the heating wire R by providing the processing chamber 202 for processing the substrate and supplying the heating power PO to the heating wire R, and is provided with a secular change sensing means for sensing the secular change of the heating wire R by sensing the supplying results, a gas feeding means for feeding a processing gas to the processing chamber and an exhaust means for discharging an exhaust from the processing chamber. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a substrate processing apparatus capable of detecting a temporal change of a heating wire in a heating device using a heater using a heating wire (for example, prediction and / or detection of disconnection).

A heater using a heating wire containing metal has a problem that the heating wire is disconnected due to deterioration due to repeated expansion and contraction due to repeated oxidation and heating / cooling of the surface.
In a furnace of a semiconductor manufacturing apparatus, expensive wafers may be processed in units of 100 to 150 at a time. When disconnection occurs during processing, not only the wafer being processed becomes a defective product but also a rapid temperature. Due to the decrease, there is a problem of causing a great deal of damage such as leading to breakage of an expensive reaction tube installed for processing a wafer inside the heater.

For this reason, the technique for foreseeing or detecting the disconnection of a heating wire conventionally is known. For example, in Patent Document 1 below, by controlling the heater of the reaction chamber in a standby state before starting the substrate processing process in which the substrate has not yet been carried into the reaction chamber, the current supplied to the heater is detected in that case. An abnormality of the heating wire (heater) is detected. In this case, the temporal change detection circuit is configured to detect a current (power supply current) when the heating power P0 is supplied to the heater R as shown in FIG. An ammeter A is connected to the supply line via a current transformer CT.
JP 2000-223427 A (pages 9 and 10 and FIGS. 22 to 32)

  However, in the above-described technique, it is possible to detect a disconnection in a normal steady operation state and to detect a current change accompanying a change in resistance value due to deterioration of the heating wire. Because the magnitude of the heating power changes slightly in order to keep the heated object constant according to changes in ambient atmospheric pressure and temperature, even during so-called temperature stabilization, If a decrease in current is detected to detect a change in heating wire over time, there is a possibility that erroneous detection may occur in some cases.

  The present invention supplies time-dependent change detection power having a high frequency different from the frequency of heating power to the heating wire, such as deterioration of the heating wire that could not be solved by the prior art, and results of supply of the power in the heating wire. It is an object of the present invention to provide a substrate processing apparatus capable of preventing erroneous detection by measuring the above.

  In order to solve the above-described problems, a substrate processing apparatus according to the present invention heats the processing chamber by supplying a first power (heating power) to a processing chamber for processing the substrate and a heating wire. Means for supplying a second electric power (time-dependent change detection power) higher than the frequency of the first electric power to the heating wire, detecting a time-dependent change of the heating wire, and the processing chamber. A gas supply means for supplying a processing gas and an exhaust means for exhausting the processing chamber are provided.

  As described above in detail, according to the present invention, it is possible to provide a substrate processing apparatus that can detect a change with time such as deterioration of a heating wire with high reliability regardless of the operating state of the substrate processing apparatus.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing the basic principle of the present invention. In FIG. 1, in order to measure the impedance of a heating wire (heater R: hereinafter, the heating wire and the heater are used as the same meaning) separately from the heating power P0, it has a high frequency (high frequency) f _D different from the heating power. detecting the power P _D and the detection unit D is provided (current, or by measuring the voltage). This is because when measurement is performed with high-frequency alternating current, not only direct current but also L and C can be measured. Incidentally, detection power P _D is configured to be superimposed on the heating power by turning on the switch SW, therefore, possible to detect the change with time of the heating wire properly by opening and closing operation of the switch SW It is. The electric power supplied from the detection power supply is the temporal change detection power of the present invention.

Referring to detect power P _D, generally the depth d of the magnitude of the current density becomes 1 / e in comparison with the surface by the skin effect when high frequency current to the conductor,

d = √ (2 / ω · μ · K) = 5.14 × 10 2 / √ (f · μ r · K) [m]
ω = 2πf μ = μ ₀・ μ _r

It is expressed.
Here, f is the frequency, μ _r is the relative permeability, μ ₀ is the vacuum permeability, and K is the conductivity.

For example, in the case of copper, f = 50 [Hz] (K = (1 / 1.69) × 10 ⁸ , μ _r = 1), d = 9.5 [mm], and f = 50 [MHz]. d = 9.5 [μm], f = 5 [GHz], and d = 0.95 [μm].

  Thus, at high frequency, current flows only on the conductor surface. As shown in FIG. 4, a new heater has a few oxidation / deterioration layers on the surface, but as shown in FIG. After local heat generation due to the rise in value, it melts rapidly and leads to disconnection. Therefore, even if the heating wire is measured at a frequency equivalent to that of the commercial power for heating, it is difficult to grasp the change in resistance value due to oxidation / degeneration of the surface. It is possible to capture.

As further to reduce the disturbance due to the frequency of the heating power source is shown in FIG. 2, by providing the filter circuit FL _D, it is possible to capture the change of heating wire wire breakage at higher sensitivity. FIG. 3 shows an example of a filter circuit, which can be configured with an LC circuit, and the detection unit D can be configured with a high-frequency ammeter A. Thus, P _D in FIG. 3, the line of A, for example, does not flow power f ₀ is, P _D, the line of A may be the only flowing power of f _D is. Incidentally, connect the voltmeter V in parallel with the high-frequency ammeter A and the sensing power supply P _D, it becomes more likely to detect when configured to detect.

  Next, the configuration of the substrate processing apparatus according to the present embodiment will be described with reference to the drawings. In the following description, a case where a vertical apparatus (hereinafter referred to as a processing apparatus) that performs diffusion processing, CVD processing, or the like is applied to the substrate as the substrate processing apparatus will be described.

  FIG. 6 is an external perspective view of the substrate processing apparatus. This figure is drawn as a perspective view. FIG. 7 is a side view of the substrate processing apparatus shown in FIG.

  In this processing apparatus, a pod (substrate storage container) 100 storing a wafer (substrate) 200 made of silicon or the like is inserted from the outside into the housing 101 and vice versa. An I / O stage (holding member exchanging member) 105 is attached to the front surface of the housing 101, and a cassette shelf (mounting means) 109 for storing the inserted pod 100 is laid in the housing 101. ing. Further, an N2 purge chamber (airtight chamber (preliminary chamber)) 102 serving as a transfer area for the wafer 200 and serving as a loading / unloading space for a boat (substrate holding means) 217 described later is provided. The N 2 purge chamber 102 is a sealed container so that the inside of the N 2 purge chamber 102 when processing the wafer 200 is filled with an inert gas such as N 2 gas in order to prevent a natural oxide film on the wafer 200. ing.

  As the pod 100 described above, the FOUP type is currently mainly used, and the opening provided on one side surface of the pod 100 is closed with a lid (not shown) to isolate the wafer 200 from the atmosphere. The wafer 200 can be transferred into and out of the pod 100 by removing the lid. A pod opener (opening / closing means) 108 is provided on the front side of the N2 purge chamber 102 so that the lid of the pod 100 is removed and the atmosphere in the pod communicates with the atmosphere of the N2 purge chamber 102. The pod 100 is transferred between the pod opener 108, the cassette shelf 109, and the I / O stage 105 by a cassette transfer machine 114. Air that has been cleaned by a clean unit (not shown) provided in the casing 101 is caused to flow in the transport space of the pod 100 by the cassette transfer device 114.

  Inside the N2 purge chamber 102, a boat 217 for loading a plurality of wafers 200 in multiple stages, a substrate alignment device 106 for adjusting the position of the notch (or orientation flat) of the wafers 200 to an arbitrary position, and a pod opener 108 A wafer transfer device (transfer means) 112 for transferring the wafer 200 between the pod 100, the substrate alignment device 106, and the boat 217 is provided. A processing chamber 202 for processing the wafers 200 is provided above the N 2 purge chamber 102, and the boat 217 is loaded into the processing chamber 202 or unloaded from the processing chamber 202 by a boat elevator (lifting means) 115. can do.

  Next, the operation of the above-described substrate processing apparatus will be described.

  First, the pod 100 that has been transported from the outside of the housing 101 by AGV, OHT, or the like is placed on the I / O stage 105. The pod 100 placed on the I / O stage 105 is directly transported onto the pod opener 108 by the cassette transfer device 114, or once stocked on the cassette shelf 109 and then transported onto the pod opener 108. The The pod 100 transferred onto the pod opener 108 is removed by the pod opener 108, and the internal atmosphere of the pod 100 is communicated with the atmosphere of the N 2 purge chamber 102.

  Next, the wafer 200 is taken out from the pod 100 in communication with the atmosphere of the N 2 purge chamber 102 by the wafer transfer device 112. The taken-out wafer 200 is aligned by the substrate alignment device 106 so that a notch is set at an arbitrary position, and is transferred to the boat 217 after alignment.

  When the transfer of the wafer 200 to the boat 217 is completed, the furnace port shutter 116 of the processing chamber 202 is opened, and the boat 217 loaded with the wafer 200 is loaded by the boat elevator 115.

  After loading, arbitrary processing is performed on the wafer 200 in the processing chamber 202. After the processing, the wafer 200 and the pod 100 are discharged out of the housing 101 in the reverse procedure described above.

  Details of the substrate processing in the processing chamber 202 will be described with reference to FIG.

  The outer tube (hereinafter referred to as the outer tube 205) is made of a heat-resistant material such as quartz (SiO2), and has a cylindrical shape with the upper end closed and the lower end opened. The inner tube (hereinafter, inner tube 204) has a cylindrical shape with openings at both ends of the upper end and the lower end, and is disposed concentrically within the outer tube 205. A space between the outer tube 205 and the inner tube 204 forms a cylindrical space 250. The gas rising from the upper opening of the inner tube 204 passes through the cylindrical space 250 and is exhausted from the exhaust pipe 231.

  A manifold 209 made of, for example, stainless steel is engaged with lower ends of the outer tube 205 and the inner tube 204, and the outer tube 205 and the inner tube 204 are held by the manifold 209. The manifold 209 is fixed to holding means (hereinafter referred to as a heater base 251). An annular flange is provided at each of the lower end portion of the outer tube 205 and the upper opening end portion of the manifold 209, and an airtight member (hereinafter referred to as an O-ring 220) is disposed between the flanges. Has been.

  A disc-shaped lid (hereinafter referred to as a seal cap 219) made of, for example, stainless steel is detachably attached to the lower end opening of the manifold 209 through an O-ring 220 so as to be hermetically sealed. A gas supply pipe 232 as a gas supply means is provided below the outer tube 205. A processing gas is supplied into the outer tube 205 through these gas supply pipes 232. These gas supply pipes 232 are connected to a gas flow rate control means (hereinafter referred to as a mass flow controller (MFC) 312). The mass flow controller 312 is connected to the gas controller 304, and the flow rate of the supplied gas is set to a predetermined level. The amount can be controlled.

  At the top of the manifold 209 is a pressure regulator (for example, APC, N2 ballast controller, hereinafter referred to as APC242) and an exhaust pipe for gas connected to an exhaust device (hereinafter referred to as a vacuum pump 246) as exhaust means. 231 is connected, and the gas flowing through the cylindrical space 250 between the outer tube 205 and the inner tube 204 is discharged, and the pressure inside the outer tube 205 is controlled by the APC 242 so that a reduced pressure atmosphere of a predetermined pressure is obtained. The pressure is detected by the pressure detecting means (pressure sensor 327) and controlled by the pressure controller 305.

  Rotating means (rotating shaft 254) is coupled to the seal cap 219, and the boat 217 and the wafer 200 held on the boat 217 are rotated by the rotating shaft 254. The seal cap 219 is connected to an elevating means (boat elevator 115) and elevates the boat 217. The conveyance controller 303 controls the rotating shaft 254 and the boat elevator 115 to have predetermined speeds.

  On the outer periphery of the outer tube 205, heaters 207 (11, 12, 13, and 14 in FIG. 9) which are heating means described later in FIG. 9 are arranged concentrically. The heater 207 detects the temperature with a temperature sensor (thermocouple) 321 (1, 2, 3, and 4 in FIG. 9) so that the temperature in the outer tube 205 is set to a predetermined processing temperature, and is controlled by the temperature controller 302.

  An example of the low pressure CVD processing method by the processing chamber 202 shown in FIG. 8 will be described. First, the boat 217 is lowered by the boat elevator 115. A plurality of wafers 200 are held on the boat 217. Next, the temperature in the outer tube 205 is set to a predetermined processing temperature while being heated by the heater 207. The inside of the outer tube 205 is filled with an inert gas in advance by the mass flow controller 312 connected to the gas supply pipe 232, and the boat 217 is lifted by the boat elevator 115 and transferred into the outer tube 205. Is maintained at a predetermined processing temperature. After the inside of the outer tube 205 is evacuated to a predetermined vacuum state, the boat 217 and the wafer 200 held on the boat 217 are rotated by the rotating shaft 254. At the same time, a processing gas is supplied from a gas supply pipe 232. The supplied gas rises in the outer tube 205 and is evenly supplied to the wafer 200.

  The inside of the outer tube 205 during the low pressure CVD process is exhausted through the exhaust pipe 231 and the pressure is controlled by the APC 242 so as to be a predetermined vacuum, and the low pressure CVD process is performed for a predetermined time.

  When the reduced-pressure CVD process is completed in this way, the gas in the outer tube 205 is replaced with an inert gas and the pressure is set to normal pressure, and then the boat elevator 115 is used to proceed to the reduced-pressure CVD process for the next wafer 200. The boat 217 is lowered and the boat 217 and the processed wafer 200 are taken out from the outer tube 205. The processed wafer 200 on the boat 217 taken out from the outer tube 205 is replaced with an unprocessed wafer 200 and is again raised into the outer tube 205 in the same manner, and a low pressure CVD process is performed.

FIG. 9 is a diagram showing a configuration relating to the temperature control system of the CVD apparatus described above.
In FIG. 9, a cylindrical processing chamber 202 is erected in the heating unit 5, and a boat 217 is inserted into the processing chamber 202 with a plurality of heated wafers 200 mounted thereon. The wafer 200 is transferred from the cassette 100 (FIG. 7) to the boat 217 by the wafer transfer device 112.

  On the outer peripheral side wall of the heating unit 5, heaters 11, 12, 13, and 14 which are heating wires for heating each zone by dividing the inside of the heating unit 5 into four zones of U zone, CU zone, CL zone, and L zone from the top. (207 in FIG. 8) is provided, and the temperature detection thermocouple 1 of the U zone for detecting the temperature of each zone and the temperature detection thermocouple of the CU zone are detected on the outer peripheral side wall of the heating unit 5 facing each heating wire. 2. A CL zone temperature detection thermocouple 3 and an L zone temperature detection thermocouple 4 are provided. The boat 217 has a lower end of the seal cap 219 supported by the elevator 115.

Power cables 15, 16, 17, and 18 are connected to the heaters 11, 12, 13, and 14 through a breaker 23 from a power input unit 24, respectively. Each power cable 15, 16, 17, 18 is provided with a power control thyristor 19, 20, 21, 22, and each thyristor 19, 20, 21, 22 in each power cable 15, 16, 17, 18 is provided. And the heaters 11, 12, 13, and 14 are connected to a temporal change detection device 35 of each heater (heating wire) via a filter circuit FL _D (see FIG. 2). In addition, current sensors 31, 32, 33, and 34 for detecting overcurrent are supplementarily provided between the thyristors 19, 20, 21, and 22 and the breaker 23. According to the present invention, the overcurrent detection current sensors 31, 32, 33 and 34 may be omitted because a change with time of the heater is detected and the overcurrent state is not caused. .

  The thyristors 19 to 22 are connected to the output side of the temperature controller 302. Output parts of thermocouples 1 to 4 are connected to the input side of the temperature controller 302. The temperature controller 302 is connected to the host controller 26. The overcurrent detection current sensors 31, 32, 33, and 34 are connected to the overcurrent prevention device 36, and the overcurrent prevention device 36 is connected to the breaker 23.

  In the above configuration, the temperature controller 302 reads the temperature from the thermocouples 1 to 4, performs control calculation, determines the heater output value, and controls the thyristors 19 to 22, thereby being supplied by the power cables 15 to 18. The power to the heaters 11 to 14 in each zone is controlled. The wafer 200 is held by the boat 217 and inserted into the processing chamber 202 by the elevator 115. The host controller 26 connects the temperature controller 302, the gas controller 304, the pressure controller 305, and the like to perform process event control as described with reference to FIG.

Heater aging detector 35 has detecting unit shown in FIG. 2 or FIG. 3 (for aging detecting power P _D and the high-frequency ammeter A), for example, a switch SW in accordance with an instruction from the host controller 26 (See FIG. 1) is opened and closed to measure the high-frequency current and detect the change with time. For example, the change with time has, as a table, the state of change with time corresponding to the measured value of the high-frequency current, and is detected as the degree of change with time by comparing the measured value with the value of the table. The degree can be displayed stepwise, for example, when the heating wire has reached the replacement time, when the disconnection is about to break, or when the disconnection has occurred. Thereby, the user can know the replacement time of the heating wire with high reliability, can efficiently replace the heating wire while avoiding the operation of the substrate processing apparatus, and can also manufacture a defective substrate. Absent. The table may be provided on the host controller 26 side.

  Although the embodiments of the present invention have been described above, the substrate processing apparatus of the present invention is not limited to a vertical type, but can be applied to a single wafer type, and is not limited to a CVD apparatus. Are used for all types of substrate processing apparatuses. Further, the type and arrangement of the heating wire are not limited to the embodiment.

In the embodiment of the present invention, the following substrate processing apparatus is disclosed.
(1) The substrate processing apparatus according to claim 1, wherein the temporal change detection means predicts a temporal change by detecting an impedance value of the heating wire.
(2) The substrate processing apparatus according to claim 1, wherein the temporal change detection means predicts disconnection of the heating wire by detecting an impedance value of the heating wire.
(3) In the substrate processing apparatus according to claim 1, an alternating current measuring instrument (current transformer and ammeter) is installed in a supply path of current (power, voltage) used for heating the processing chamber. A substrate processing apparatus.
(4) In the substrate processing apparatus according to claim 1, in the second power (power, voltage) supply path, the first power frequency is a non-pass band and the second power frequency is a pass band. A substrate processing apparatus comprising a circuit.
(5) A heating device composed of a heating wire containing metal, wherein the time-dependent change detection power having a frequency higher than the frequency of the heating power is applied to or superposed on the heating wire, and the application or superposition result is detected. A heating apparatus, comprising: a temporal change detection means for detecting a temporal change of the heating wire.
(6) The heating apparatus according to (5), wherein an alternating current measuring device (current transformer) is provided along a supply path of a heating current (power, voltage) supplied to the heater.
(7) The heating device according to (5), wherein a filter circuit is provided in the supply path of the second power (current, voltage).
(8) a processing chamber for processing the substrate;
Heating means for heating the processing chamber by applying a first power to a heating wire containing metal;
Detecting means for detecting a change over time of the heating wire by applying or superimposing a second power having a frequency higher than the frequency of the first power to the heating wire;
Gas supply means for supplying a processing gas to the processing chamber;
Exhaust means for exhausting the processing chamber;
A method for manufacturing a semiconductor device for processing using a substrate processing apparatus, characterized in that the substrate processing apparatus includes a transfer means for transferring a substrate,
Transporting the substrate to the processing chamber by the transport means;
Applying the first power to the heating wire;
Applying the second power to the heating wire;
Flowing a processing gas into the processing chamber by a gas supply means;
Processing the substrate in the processing chamber;
Evacuating the processing chamber with the exhaust means.

FIG. 3 is a circuit diagram for detecting change with time showing the basic principle of the present invention. It is a circuit diagram for a time-dependent change detection using a filter. FIG. 3 is a circuit diagram illustrating an example of the filter of FIG. 2 in detail. It is a figure which shows the cross section of a new heating wire. It is a figure which shows the cross section of the deteriorated heating wire. It is a perspective view which shows an example of the substrate processing apparatus of this invention. It is a side view which shows the outline of the substrate processing apparatus of FIG. It is a side view which shows a process chamber. It is a figure which shows the structure regarding the temperature control system of the substrate processing chamber of this Embodiment. It is a time-dependent change detection circuit diagram which detects the time-dependent change of the conventional heating wire.

Explanation of symbols

P0 heating power (power), CT current transformer, A high-frequency current meter, R, 11 to 14 heating wire (heater), P _D sensing power supply, FL _D filter, 35 a heater interval change detection device, 200 a wafer (substrate) 202, processing chamber, L inductance (2 coils, etc.), C capacitance (capacitors, etc.).

Claims (1)

A processing chamber for processing the substrate;
Heating means for heating the processing chamber by supplying first electric power to the heating wire;
A change with time detecting means for detecting a change with time of the heating wire by supplying a second power higher than the frequency of the first power to the heating wire and detecting the supply result;
Gas supply means for supplying a processing gas to the processing chamber;
A substrate processing apparatus comprising: exhaust means for exhausting the processing chamber.

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