JP2000223427A - Method of detecting abnormality of heater of semiconductor manufacture device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the foreknowledge of disconnection of a heater, the detec tion of disconnection, and the detection of short circuit (prevention of overcurrent) at low cost, by detecting the abnormality of the heater in a reaction chamber, in the standby condition before start of board treatment process where a board is not carried in the reaction chamber yet. SOLUTION: When the heater is in standby condition, this method is provided with a temperature diagnosis event 1 and a temperature diagnosis invent 2 so that it may not affect the wafer process treatment, and the prevention of overcurrent (heater short circuit) and the detection of short circuit of the heater or the wire breaking are performed. The temperature diagnosis invent 1 detects the degree of abnormality in stages, based on the difference between the I value at the time of a temperature regulator controlling the temperature on PID basis and an I value acquired in advance. The temperature diagnosis event 2 is one which seeks to detect the degree of abnormality, based on whether it reaches the specified temperature or not, or the time until its reaching the specified temperature, as against the fixed heater output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a heater abnormality in a semiconductor manufacturing apparatus such as a CVD apparatus having a heating furnace.

[0002]

2. Description of the Related Art For example, in a CVD apparatus, a substrate such as a silicon wafer is accommodated in a reaction chamber, which is a heating furnace, and a reaction gas is supplied while controlling the temperature of the reaction chamber at a predetermined temperature. Semiconductor manufacturing for forming a thin film is performed. In such semiconductor manufacturing, the temperature conditions in the heating furnace are extremely important, and the accuracy of this temperature control greatly affects the substrate quality.

[0003] In order to maintain the accuracy of temperature control, it is necessary that breakage of the heater coil, short circuit, and failure of the temperature sensor and the like do not occur. The heating temperature at the time of manufacturing a semiconductor generally ranges from 500 ° C. to 1300 ° C., and the heater is usually operated continuously regardless of day and night. Therefore, the life of the heater is as short as one or two years. More than 10 years ago, a heater such as a silicon wafer was housed in a heating furnace, and a heating gas was supplied to the heating furnace while heating the inside of the heating furnace to a predetermined temperature to form a thin film on the substrate. In the case where the heater coil has reached the end of its service life and the heater coil is disconnected, 100 or more silicon wafers are wasted and a great loss may occur. In order to prevent this, in recent years, a dedicated heater disconnection detection device and a dedicated overcurrent prevention function device have been attached.

FIG. 33 is an overall configuration diagram showing such a conventional CVD apparatus. In FIG. 33, a tubular reaction tube 8 is provided upright in a heating unit 5, and a wafer boat 6 serving as a heating object holding unit is provided with a plurality of wafers 7 serving as heating objects in the reaction tube 8.
Is loaded and inserted. The wafer 7 is transferred from the wafer cassette (not shown) to the boat 6 by the transfer device.

On the outer peripheral side wall of the heating unit 5, a heating unit (heater) for heating each zone by dividing the inside of the heating unit 5 into four zones of a U zone, a CU zone, a CL zone, and an L zone from the top.
11, 12, 13 and 14 are provided, and on the outer peripheral side wall of the heating section 5 opposed to each heating section, a temperature detection thermocouple 1 of a U zone for detecting a temperature of each zone, and a temperature detection thermocouple of a CU zone are provided. A pair 2, a temperature detection thermocouple 3 in the CL zone, and a temperature detection thermocouple 4 in the L zone are provided. Boat 6
A cap 9 is provided at a lower portion thereof, and the end of the cap 9 is supported by the elevator 10.

Power cables 15, 16, 17, and 18 are connected to the heat generating units 11, 12, 13, and 14 from a power input unit 24 via a breaker 23. Each power cable 15, 16, 17, 18 is provided with a thyristor 19, 20, 21, 22 for power control, respectively.
Each thyristor 19,20,21,22 in each power cable 15,16,17,18 and each heating part 11,12,
13 and 14, current sensors 27, 28, 29 and 30 for detecting a heater disconnection of each heat generating portion are provided, and an overcurrent is provided between each of the thyristors 19, 20, 21 and 22 and the breaker 23. Detection current sensors 31, 32, 33, and 34 are provided.

[0007] The thyristors 19 to 22 are connected to the output side of the temperature controller 25. The output side of the thermocouples 1 to 4 is connected to the input side of the temperature controller 25. The temperature controller 25 is connected to a host controller 26.
The heater disconnection detecting current sensors 27, 28, 29.30 are connected to the heater disconnection detecting device 35, and the overcurrent detecting current sensors 31, 32, 33, 34 are connected to the overcurrent preventing device 36, and the overcurrent preventing device is connected. 36 is connected to the breaker 23.

In the above configuration, the temperature controller 25 reads the temperature from the thermocouples 1 to 4, performs a control operation, determines the heater output value, controls the thyristors 19 to 22, and thereby controls the power cables 15 to 18 controls the power supplied to the heaters 11 to 14 in each zone. The wafer 7 is held by a boat 6 and inserted into a reaction tube 8 by an elevator 10. The cap 9 is used for heat retention. The host controller 26 includes a temperature controller 25
Further, a gas controller, a mechanical controller, a pressure controller, and the like (not shown) are connected through communication to perform process event control.

The current sensors 27, 28,
29.30 detects the current flowing to each of the heat generating units 11, 12, 13, and 14. The heater disconnection detecting device 35 detects the heater disconnection based on the current values of the current sensors 27, 28, 29, 30. Also, the overcurrent detection sensors 31, 32,
33, 34 are each thyristors 19, 2 from the breaker 23.
The current flowing to 0, 21, 22 is detected. When an overcurrent is detected based on the current values of the current sensors 31, 32, 33, and 34, the overcurrent prevention device 36 generates an interlock signal, cuts off the breaker 23, and cuts off the power input.

[0010]

As described above, in the heater abnormality detection in the conventional semiconductor manufacturing apparatus, since a plurality of dedicated devices for detecting the abnormality are attached, a plurality of monitoring controllers are required. As a result, economic waste such as the necessity of a plurality of user interfaces occurs, and the cost performance and the maintainability are not good.

An object of the present invention is to solve the problems of the prior art, such as the economic waste and the poor cost and maintainability, and to reduce the cost (for example, by performing centralized management). Accordingly, it is an object of the present invention to provide a method for detecting a heater abnormality in a semiconductor manufacturing apparatus capable of performing heater disconnection prediction, disconnection detection, and short circuit detection (overcurrent prevention).

[0012]

In order to solve the above-mentioned problems, a method of detecting a heater abnormality in a semiconductor manufacturing apparatus according to the present invention is performed in a standby state before starting a substrate processing process in which a substrate has not yet been carried into a reaction chamber. And a heater abnormality detecting step for detecting a heater abnormality in the reaction chamber.

In the present invention, the standby state is a state where a wafer is transferred from a wafer cassette to a wafer boat.

Further, in the present invention, the heater abnormality detecting step is a step of judging whether or not the I output value in the PID control of the reaction chamber temperature is appropriate.

Further, in the present invention, the heater abnormality detecting step varies the heater output value, and determines the abnormality based on the resulting temperature fluctuation in the reaction chamber.

Further, in the present invention, after the temperature change, the temperature is controlled so that the temperature in the reaction chamber returns to the state before the change during the standby state.

Further, in the present invention, the determination in the heater abnormality detecting step is made based on a time until the temperature fluctuation in the reaction chamber reaches a predetermined value.

Further, in the present invention, if the time required to reach the predetermined value is longer than a reference value, it is determined that the heater is disconnected.

In the present invention, if the time required to reach the predetermined value is shorter than a reference value, it is determined that the heater is short-circuited.

Further, according to the present invention, in an apparatus having a multi-zone heater, any one of the zones may be provided.
The above-described heater abnormality detection method is used.

In the present invention, the step of detecting a heater abnormality determines the presence or absence of an abnormality based on a current value flowing through the heater.

Further, in the present invention, if the current value is smaller than the reference value, it is determined that the heater is disconnected.

Further, in the present invention, when the current value is larger than the reference value, it is determined that the heater is short-circuited.

Further, in the present invention, a plurality of reference values of the detection value used for determining the presence / absence of the abnormality of the heater are set according to the temperature in a standby state.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows Embodiment 1
FIG. 1, the same reference numerals as those in FIG. 33 denote the same or corresponding components as in FIG. 33, and a description thereof will be omitted. In FIG. 1, the CV shown in FIG.
For the D device, the heater disconnection detection current sensors 27, 2
8, 29, 30, the heater disconnection detection device 35, the overcurrent detection current sensors 31, 32, 33, 34, and the overcurrent prevention device 36 are eliminated.

In the above configuration, the temperature controller 25A reads the temperature from the thermocouples 1, 2, 3, and 4 and performs a control operation to determine a heater output value.
By controlling the heaters 21 and 22, the heater 1
By controlling power supply to 1, 12, 13, and 14, the temperature of the reaction chamber (in the reaction tube 8) is controlled. The wafer 7 as a heating object is transferred from a wafer cassette (not shown) to a wafer boat 6 and held by the boat 6, and the elevator 10
Is inserted into the reaction tube 8.

The host controller 26A includes a temperature controller 2
5A and other gas controllers, mechanical controllers, pressure controllers, and the like (not shown) are connected by communication to perform process event control. Also, the upper controller 26
A performs heater disconnection detection and overcurrent prevention using the temperature read from the thermocouples 1 to 4 by the temperature controller 25A and the I (integral element) output value obtained as a result of internal calculation by the temperature controller 25A. At that time, the breaker 23 is turned off and the power input unit 24 is cut off by the interlock signal.

FIG. 2 is a block diagram showing details of the temperature controller. The temperature controller 25A includes a CPU 250, a memory (for a program) 251, a memory (for a work) 252,
It comprises an AD converter (for thermocouple) 253, a MUX (thermocouple multiplexer) 254, and a communication control unit 256 used for communication with the host controller 26A, and generates a thyristor firing pulse and an interlock signal as required.

The temperature controller 25A performs the following PID calculation using PB, I, and D as constants. Deviation = Set temperature value−Measured temperature value PID output value = P output value + I output value + D output value P output value = 100 × deviation ÷ PB (1) I output value = 100 ÷ PB ÷ I × deviation time integration value D output Value = 100 ÷ PB x D x deviation time derivative

FIG. 3 is a block diagram showing details of the host controller. The upper controller 26A is provided with the CPU 26
0, a memory (for a program) 261, a memory (for a work) 262, an external storage unit 263, a display control unit 264, a display device 265, and a communication control unit 266, and generate an interlock signal as needed.

FIG. 4 is a sequence diagram of one batch process conventionally performed by the host controller 26. The host controller 26 connects the temperature controller 25 and other gas controllers (not shown), a mechanical controller, a pressure controller, and the like via communication, and performs process event control. The wafer 7 is processed according to the gas flowing into the reaction tube 8, the pressure in the reaction tube, and the temperature. The transfer of the wafer 7 is performed by a mechanical controller, a gas controller controls a gas flow rate, and a pressure controller controls a pressure. Then, the temperature controller 25 controls the temperature.

It is the host controller that centrally manages these distributed controllers and has a user interface, and instructs the distributed controllers on processing events under time management.

In FIG. 4, in the standby state (during standby recipe RUN) (1), each dispersion controller is in a ready state, and no boat has been inserted into the reaction tube. In the meantime, a product wafer lot input instruction is issued. The lot input instruction is performed by sending input lot information from the host computer or by inputting the input lot information by the operator. Then, the process recipe RUN is instructed. This process recipe RUN instruction is also performed by the host computer sending the instruction or by the operator inputting the instruction, similarly to the lot input instruction.

After the wafer is transferred from the cassette to the boat based on the input lot information (product wafer charge), the boat is inserted into the reaction tube by instructing the mechanical controller to perform a boat up event (2).
Thereafter, if necessary, a ramping event of gradually increasing the temperature is instructed to the temperature controller (3).
After the completion of the ramping, a wafer process is performed by gas inflow and pressure adjustment (4). After the completion of the processing, a ramping event is instructed to the temperature controller (5).

After the ramping is completed (6), a boat down start event is instructed to the mechanical controller (7), so that the boat is taken out of the reaction tube. After the boat down is completed (8), the wafers loaded on the boat are carried out to a predetermined position on the transfer shelf (product wafer discharge). When the above process recipe is completed, the process returns to the standby state (9).

In the embodiment of the present invention, in the standby state, as shown in FIG.
A temperature diagnosis event 2 is provided so as not to affect the wafer process processing, to prevent overcurrent (short circuit of the heater), short circuit of the heater, and disconnection detection.

The temperature diagnosis event 1 is performed based on the difference (ratio) between the value of I when the temperature controller controls the PID temperature and the value of I obtained in advance in the standby temperature state. It is intended to detect the degree of abnormality abnormally.

That is, the I output value refers to the I output value of the result of the PID control operation, and is represented by the above-described equation (1). In the temperature stable period, since the deviation is almost 0, the P output value becomes 0, the D output value becomes 0, and the I output value becomes stable. As a method for use in the temperature diagnosis event 1, first, an I output value is obtained at the standby temperature. The upper limit 1, the attribute, the upper limit 2, the attribute, the lower limit 1, the attribute, the lower limit 2, and the attribute are set for each zone. In the event of an abnormality, an abnormality is detected based on this value, utilizing the fact that the I output value is no longer an appropriate value.

In the case of the temperature diagnosis event 1, the boat is not inserted into the reaction tube, and when compared with the wafer transfer time, the detection of the heater short-circuit (prevention of overcurrent), the detection of the heater disconnection, or the prediction time for these. Is short, so that the entire sequence time is not extended. This method can be used even if the temperature is stable during the process, not during standby, if you want to use it. However, if the heat capacity of the wafer changes when the boat (wafer mounted state) is inserted into the reaction tube, Since the I output value, which is the temperature stable output value of the heater, differs, accurate abnormal measurement cannot be performed. Further, depending on the temperature transition history, the I output value of each zone has some variation, so that the I output value is slightly less accurate than when the temperature diagnosis event 1 is used.

On the other hand, the temperature diagnosis event 2 is based on whether or not a predetermined check temperature is reached for a fixed heater output or the time until the predetermined temperature is reached (by comparing with a normal heater output). Based on this, the degree of abnormality is to be detected. Temperature diagnosis event 2
In this case, the boat is not inserted into the reaction tube, and is not affected by the heat capacity of the boat or the wafer. A method of outputting a predetermined fixed heater output value for each zone and observing a transient temperature thereof requires time for checking.

For example, if it takes 15 minutes to check one zone, it takes 60 minutes for four zones. This is about the same or longer than the wafer transfer time, and may affect the apparatus throughput. When the temperature controller is not in the temperature diagnosis event 2, normal control calculation processing is performed.
Some of them have a feature that control is performed using a fixed heater output value. In this method, the temperature observation is performed, for example, in the U zone 100% and the other zone 0% in order to prevent the influence of the thermal interference between the zones. When the temperature is observed, it becomes impossible to determine whether or not the heater has an abnormality due to thermal interference between zones.

As a method of using the temperature diagnosis event 2, first, a time exceeding the check temperature is obtained from the heater output fixed at the standby temperature. Set the upper limit time, attribute, lower limit time, and attribute for each zone. In the event of an abnormality, the fact that the time exceeding the check temperature is not an appropriate value is used. The limit temperature is for ensuring safety. When the temperature exceeds the limit temperature, the normal control state (PID control)
And returned to standby temperature.

Here, either one of the temperature diagnosis event 1 and the temperature diagnosis event 2 may be used, or both may be used. Ordinarily, only the temperature diagnosis event 1 may be performed, and in a specific case, the temperature diagnosis event 2 may be used. In this case, for example, an error event jump is specified by an attribute, and a temperature diagnosis event 2 is defined as an error event jump destination, and when an error event occurs, diagnosis of only a zone considered to be abnormal is performed again. To increase the reliability of error detection. In this combination case, the device throughput is not affected.

Although the two heater abnormality detection methods do not use a current detector and thus do not require a cost, they use indirect measurement through temperature in terms of accuracy, and are therefore better than those using a current detector. There is no, but it can be used as a simple one.

In order to execute the above-mentioned event, in the standby state, as shown in FIGS. 6 and 8, the higher-level controller sets the standby temperature to 500 ° C., the standby temperature 600 ° C., and the standby temperature 1000 ° C. It has a temperature alarm condition table for inputting numerical values. As shown in these figures, there are two types of temperature alarm condition tables corresponding to the two diagnostic methods. Each of the two types of temperature alarm condition tables (temperature alarm condition table T1 and temperature alarm condition table T2) includes, for example, ten standby temperature correspondence tables.

The reason why a plurality of (ten types) of standby temperatures are prepared is that each zone heating section 11 to 14 of the heating section (heater) is prepared.
Has a characteristic that the resistance changes depending on the temperature, so even at the same voltage, the measured current value is different and the transient temperature characteristic is different, so by having a plurality of standby temperatures, fine setting is possible. That's because.

FIG. 6 shows the temperature alarm condition table T1, and FIG. 7 shows the I value history corresponding to the temperature alarm condition table T1. 8 shows a temperature alarm condition table T2, FIG. 9 shows a temperature history corresponding to the normal temperature alarm condition table T2, and FIG. 10 shows a temperature history corresponding to the abnormal temperature alarm condition table T2. It is. 6 and 8 show the tables T1 and T2 on the editing screen of the host controller.

In FIG. 6, an upper limit 1, an attribute, an upper limit 2, an attribute, a lower limit 1, an attribute, a lower limit 2, and an attribute can be defined for each zone in the standby temperature correspondence table in the temperature alarm condition table T1. Here, upper limit 1 (disconnection criterion) and lower limit 2 (short circuit criterion) define a limit at which a severe alarm should be generated, and upper limit 2 (disconnection prediction criterion) and lower limit 1 (short circuit prediction criterion) generate a slight alarm. It defines the limits to be set. The attributes can define an interlock signal, an alarm occurrence, a buzzer sound, a reset, an error event jump, and the like, and indicate an operation event when the value is out of an appropriate range.

Here, "reset" means shifting to a reset pattern. In the reset pattern, for example, an error process when an abnormality occurs, such as “drop the temperature to 200 ° C.”, has already been described. The interlock refers to, for example, generating an event such as forcibly turning off a breaker of a heater. The occurrence of an alarm means that the screen display is changed to an alarm display, and the sounding of a buzzer means a sound notification. In the embodiment, an interlock signal is generated for the severe alarm and an alarm is generated for the mild alarm. However, it is needless to say that these can be appropriately combined.

The above-mentioned tables are edited by the editing operation on the editing screen shown in FIG. 6, and after editing, they are saved and stored in the external storage device. Downloading means that the displayed table is used as the current temperature alarm condition table T1 in the system,
Uploading means displaying the current temperature alarm condition table T1 in the system. According to the temperature alarm condition table T1, the heater disconnection prediction, disconnection detection, and overcurrent prevention functions can be centrally managed as described later, and prompt notification to the user and the safety performance of the device can be improved.

The I value history graph of each zone shown in FIG. 7 is shown in the upper controller, and displays the upper limit 1, the upper limit 2, the lower limit 1, and the lower limit 2 in the temperature diagnosis event 1, and the temperature controller performs internal calculation. The I output value obtained as a result is displayed in real time including the past history, and whether or not there is any abnormality can be visually checked. The operation by this will be described later.

In the temperature alarm condition table T2 shown in FIG. 8, a plurality of standby temperature correspondence tables in the temperature alarm condition table T2 include a check temperature, a fixed heater output value, an upper limit time, an attribute, and a lower limit time for each zone. , Attributes are defined, and attributes include interlock signals,
Alarm generation, buzzer sounding, reset, error event jump, etc. are defined, and indicate an operation event when the value goes out of an appropriate range.

In each standby temperature correspondence table,
The limit temperature is for ensuring safety. When the temperature exceeds the limit temperature, the normal control state is returned. For example, in the case of the table with the standby temperature of 500 ° C. in the drawing, this event operates at the standby temperature of 500 ° C. For example, when checking the abnormality of the heater zone of CH1, the CH1 (U) zone 40%, CH2 (L) zone 0%, CH3 (CU) zone 0%, CH4 (CL)
This means that a fixed heater output value of zone 0% is output. The check temperature at that time is 500 + 50 = 550 ° C
And the limit temperature is 500 + 50 + 50 = 600 ° C
It is. The upper limit time indicates the time from when it is determined that the temperature of all zones is stable after the start of the event. The same applies to the lower limit time.

In the temperature history graph corresponding to the temperature alarm condition table T2 of each zone shown in FIG. 9, during normal operation, the CH1 (U) zone is 40% and the CH2 (L) zone is 0.
%, CH3 (CU) zone 0%, CH4 (CL) zone 0% output, the temperature of CH1 zone rises,
The temperatures of 2 to 4 decrease. Then, the temperature of the CH1 zone exceeds the check temperature between the upper limit time and the lower limit time. If the temperature exceeds the limit temperature, the normal P
The temperature recovers towards 500 ° C. to return to ID control.

The temperature history graph corresponding to the temperature alarm condition table T2 of each zone indicating the abnormal time shown in FIG. 10 will be described with reference to the schematic diagram of the heater resistance line in FIG. C
One of four zones, H1 zone, CH2 zone, CH3 zone, CH4 zone, for example, CH1
Pay attention to the zones. The heater in one zone is, for example, as shown in FIG.
Assuming that it has a parallel circuit shown in Fig.
At 0, the following temperature behavior may be exhibited.

FIG. 11A shows an example in which an overcurrent due to a short circuit flows through the resistance wires A and B to reach the check temperature in a shorter time than the upper limit time as shown in FIG.
As shown in (b), an example is shown in which the check temperature is reached in a time longer than the lower limit time due to the disconnection of the resistance wire A. In this case, the heater in that zone may be disconnected. FIG. 11C shows an example in which the check temperature cannot be reached due to disconnection of the resistance wires A and B as shown in FIG. Due to the heat interference, the detected temperature of the CH1 thermocouple was seen as 500 ° C. due to the heat of the heater in the adjacent CH2 zone.

Hereinafter, in Embodiment 1 of the present invention,
The processing operation will be described with reference to a flowchart. FIG. 12 is a flowchart of the temperature diagnosis event switching monitoring process of the host controller. This processing is provided as a subroutine of the main processing routine of the upper controller shown in FIG. 19. In step S1, temperature diagnosis event 1 processing is performed. In step S2, temperature diagnosis event 2 processing is performed. I do.

These event times are controlled using an internal timer, and when the time is up, an instruction corresponding to the next event is transmitted to the temperature controller using a communication line. As described above, for the temperature diagnosis events 1 and 2, only the event 1 may be executed at all times, and the event 2 may be executed when the event 1 has an abnormality, as described above.

FIG. 13 is a flowchart showing the details of the processing of the temperature diagnosis event 1 shown in FIG.
In this process, first, in step S11, it is determined whether or not it is the temperature diagnosis event 1 start time. In the case of the start time, the averaging start flag is set to 0 in step S12, and the flag during the temperature diagnosis event 1 is set to 1 in step S13.

Here, the averaging start flag is used for checking the temperature diagnosis event 1 of the host controller described later (FIG. 2).
This is because the processing is different between the first processing and the subsequent processing. In addition, temperature diagnosis event 1
The middle flag indicates the main processing of the upper controller (FIG. 19)
Is used to determine whether or not the event 1 is being performed.

On the other hand, if it is determined in step S11 that the time is not the start time of the temperature diagnosis event 1, the process proceeds to step S14, where it is determined whether or not the event time of the event 1 has ended. If it is determined that the process has been completed, the process proceeds to step S15, where the final result of the I value averaged in the process of FIG. 20 is stored as a history in the external storage device. This can be used later as historical data. In step S16, the flag during the temperature diagnosis event 1 is set to 0, and it is determined that the event time has ended in the main processing of the host controller.

FIG. 14 is a flowchart showing the details of the temperature diagnosis event 2 processing shown in FIG. In this process, first, in step S21, it is determined whether or not the time is the start time of the temperature diagnosis event 2, and if it is determined that the time is the start time, the process proceeds to step S22 to perform a temperature stable state check process. This is a process performed as a precondition for detecting a heater abnormality, as a start condition that the temperature in the reaction chamber is stable without being in an excessive state.

If it is determined in step S23 that all zones are in the temperature stable state, step S24
Then, the temperature controller is notified of the start of the temperature diagnosis event 2 by a communication message. This message includes a fixed heater output value of each zone described later and a fixed heater output value control designation. This interrupts the main processing of the temperature controller, and the processing shown in FIG. 15 described below is started. Then, the flag during the temperature diagnosis event 2 is set to 1 in step S25. This flag is used in the main processing of the host controller shown in FIG. On the other hand, if it is determined in step S23 that the temperature is not stable, the process proceeds to step S2.
The processing of steps 4 and 25 is skipped and the processing ends.

If it is determined in step S21 that the time is not the start of the temperature diagnosis event 2, the process proceeds to step S26, where it is determined whether or not the end time of the temperature diagnosis event 2 has been reached. In step S27, the end of the temperature event 2 is notified by a communication message to the temperature controller to start the interrupt processing of FIG. 15, and the flag in the temperature diagnosis event 2 is set to 0 in step S28, and To end. If it is not the end of the temperature diagnosis event 2 in step S26, the processing in FIG.

FIG. 15 shows a flowchart of the temperature controller interrupt started by notification from the host controller. First, in step S31, it is determined whether or not the message is the start of the temperature diagnosis event 2, and in step S32, a fixed heater output value control start process of FIG. On the other hand, if it is determined in step S31 that the message is not the start of the temperature diagnosis event 2, the process proceeds to step S33 to determine whether the temperature diagnosis event 2 is completed. And if it is finished, step S
Proceeding to 34, the fixed heater output value control end processing of FIG. If it is determined in step S33 that the temperature diagnosis event 2 is not to be ended, the interrupt processing is ended, and the temperature diagnosis event 2 is continued.

FIGS. 16A and 16B are flowcharts respectively showing the processing contents of steps S32 and S34 of the processing shown in FIG. In the process of FIG. 16A (the process of step S32), first, in step S41, the fixed heater output value control flag is set to 1, and in step S42, the fixed heater output value of each zone is set in the table. .

In the processing of FIG. 16B (processing of step S34), first, in step S51, the fixed heater output value control flag is set to 0, and in step S5
In step 2, a fixed heater output value of 0% for each zone is set in a table.

FIG. 17 is a main flowchart showing the main processing of the temperature controller. First, for initialization of the operation start, the fixed heater output value control flag is set to 0 in step S61, the fixed heater output value 0% of each zone is set in a table in step S62, and in step S63, Set the zone limit temperature 0 ° C on the table.

In step S64, it is determined whether the fixed heater output value control flag is "1". If it is "1", in step S65, a thyristor gate pulse corresponding to the fixed heater output value set in the table is set. Output a signal. In step S66, the temperature is detected, and the detected temperature is notified to the host controller. The notified temperatures are received in the processing shown in FIG. 18 described later, and these temperatures are used in the processing of the higher-level controller (FIG. 21) described later.

On the other hand, if it is determined in step S64 that the control flag is not "1", the process proceeds to step S67.
, A control operation (PID operation) is performed to calculate a heater output value, and in step S68, a thyristor gate pulse signal corresponding to the heater output value as a result of the control operation is output, and the process proceeds to step S66. Note that these processes include control in normal wafer processing.

FIG. 18 is a flowchart showing processing for receiving a message from the temperature controller in the host controller.
If it is determined in step S71 that the received message is a temperature, in step S72, the received temperature value of each zone is set in the temperature table, and the process ends. If it is determined in step S71 that the received message is not at the temperature, the process is immediately terminated.

FIG. 19 shows a main flowchart of the host controller. As a main operation of the host controller, first, for initialization, in step S81, the flag during the temperature diagnosis event 1 is set to 0, and in step S81,
At 82, the flag during the temperature diagnosis event 2 is set to 0.

Steps S83 to S87 are a permanent loop routine that is repeated until the power is turned off. First, in step S83, the event switching monitoring process shown in FIG. 12 is performed, and in step S84, it is determined whether the flag during the temperature diagnosis event 1 is “1”. If the flag is “1”, step S
At 85, a temperature diagnosis event 1 check process is performed. This processing will be described later with reference to FIG.

Then, in step S86, it is determined whether or not the flag during the temperature diagnosis event 2 is "1". If the flag is "1", the temperature diagnosis event 2 check processing is performed in step S87. . This processing will be described later with reference to FIG. If the flag is not “1” in step S84 or step S86, the process returns to step S83, and the same processing is repeated.

Next, the temperature diagnosis event 1 check processing by the host controller will be described with reference to FIG. First, in step S91, a process for checking a stable temperature state is performed. This is a prerequisite for starting the heater abnormality determination process in a stable state of the temperature of the reaction chamber. If it is determined in step S92 that the temperatures of all the zones are in a stable state, the process proceeds to step S9.
Then, it is determined whether or not the averaging start flag is “0”. If the averaging start flag is “0”, the current (current) I output value is set to the I average value in step S94. In step S95, the averaging start flag is set to "1", and the process ends.

On the other hand, if the averaging start flag is not "0" in step S93, the flow advances to step S96 to calculate the average value of the I value by adding the current I output value to the I average value and dividing by two. I do. Next, step S
The process proceeds to step S97, where the standby temperature is searched to check the contents of the condition corresponding to the standby temperature in the temperature alarm condition table T1, and the process proceeds to step S98.

At step S98, it is determined whether or not the I average value is not less than the upper limit 1 of the temperature alarm condition table. If not, at step S99, whether or not the I average value is not less than the upper limit 2 is determined. If it is determined that it is not equal to or more than the upper limit 2, the process proceeds to step S100, and it is determined whether or not the I average value is equal to or more than the lower limit 1 of the temperature alarm condition. Is determined. After the process of step S101, each of steps S98, S99,
When the result of the determination in step S101 is affirmative and after the processing in step S101, it is determined that there is a serious or mild abnormality, and the process proceeds to step S102. On the other hand, step S1
If the determination result of step 00 is affirmative (ie, less than the upper limit 2 and not less than the lower limit 1), there is no abnormality and step S10
The processing is terminated without going through step 2.

Then, in step S102, the four pattern determination results determined in steps S98 to S101 (if the upper limit is 1 or more (disconnection), the upper limit 1
When the value is smaller than the upper limit 2 or more (disconnection prediction), when the value is smaller than the lower limit 1 and is 2 or more (short-circuit prediction), and when the value is 2 or less (short-circuit), the processing for the predetermined attribute determined for each is performed. Done. For example, as described above, the attribute is a serious abnormality when the upper limit is 1 or more (disconnection) and the lower limit 2 or less (short circuit), when the upper limit is 1 and the upper limit is 2 or more (disconnection prediction), and when the lower limit is 1 and the lower limit is 2 or more. (Shorting prediction) is assumed to be slightly abnormal, and lower than 1 and lower than 1 is considered normal. For example, an interlock signal, alarm generation, buzzer sounding, reset, error event jump, etc. are appropriately applied to these when abnormal. And an operation event when the value is out of the appropriate range.

Next, the temperature diagnostic event 2 check processing by the host controller will be described with reference to FIG. First, in step S111 at the start of this subroutine, it is determined again whether or not the flag during the temperature diagnosis event 2 is “1”. If “1”, the process proceeds to step S112, where the temperature alarm condition is set. The standby temperature is searched to check the contents of the condition corresponding to the standby temperature in the table T2.

Next, in step S113, it is determined whether or not the current temperature is higher than the check temperature. If it is higher, in step S114, the upper limit time is longer than the current time, that is, the current time has not yet reached the upper limit time. If the upper limit time is not longer than the current time, it is determined in step S115 whether the current time is longer than the lower limit time, that is, whether the current time has passed the lower limit time.

If the current temperature is not higher than the check temperature in step S113, the process in step S115 is performed. If the upper limit time is longer than the current time after the process in step S115 or in step S114. If determined, step S
At 116, similarly to FIG. 20, a definition attribute correspondence process is performed. This processing is performed in steps S113 to S113.
At 115, three patterns to be determined (when the current temperature is higher than the check temperature and the upper limit time is longer than the current time (FIG. 10), when the current temperature is higher than the check temperature and the current time is longer than the lower limit time (FIG. 10) ), And is a predetermined corresponding process that is defined corresponding to the case where the current temperature is equal to or lower than the check temperature and the current time is longer than the lower limit time (FIG. 10).

Then, in step S117, it is determined whether or not the current temperature is higher than the limit temperature.
If it is larger, in step S118, the end of the temperature diagnosis event 2 is notified to the temperature controller.
At 119, the flag during the temperature diagnosis event 2 is set to “0”.
And the process ends. If the current time is not greater than the lower limit time in step S115, or if the current temperature is not greater than the limit temperature in step S117, the process ends.

As described in detail above, according to the first embodiment, heater disconnection detection,
Overcurrent can be prevented. In addition, for example, 500 ° C.
At a predetermined stable process temperature such as 600 ° C. or 600 ° C., the temporal change in the heater output value is recorded, and a case where the heater output value gradually fluctuates is detected. You can also.

Embodiment 2 In the first embodiment, the abnormality of the heater is detected from the temperature fluctuation with respect to the predetermined heater output or the I value output fluctuation. In the second embodiment, the abnormality is detected by detecting the current value to the heater. It is like that. Therefore, in the process processing sequence in the second embodiment, the same sequence as that in the case of using the temperature diagnosis event 1 in FIG. 5 used in the first embodiment can be used. Hereinafter, Embodiment 2 will be described. In the second embodiment, the same reference numerals as those in the first embodiment denote the same or corresponding components.

FIG. 22 is a diagram showing the overall structure of a CVD apparatus according to the second embodiment. In the first embodiment, the current sensors 27, 28, 29, and 30 are different from the first embodiment in that heaters (heating units 11, 12) are provided in each zone. , 13, 14) are provided on the power cables 15, 16, 17, 18 respectively.

FIG. 23 is a diagram showing the overall configuration of the temperature controller. An AMP 257 and a rectifier circuit 25 serve as input interfaces from the current sensors shown in FIG.
8, a multiplexer 259, and an AD converter 260.

FIG. 24 shows a current alarm condition table on the upper controller editing screen. As shown in FIG.
° C, temperature range 100-199 ° C, temperature range 200-299 ° C
And has a current alarm condition table in which numerical values of the temperature zone can be input. The current alarm condition table is composed of 20 temperature zone correspondence tables. These have the characteristic that the resistance of each zone heating section of the heating section (heater) changes depending on the temperature, and the allowable current value differs even at the same voltage. Is made possible.

Then, in each temperature zone correspondence table,
For each zone, fixed heater output value, upper limit 1, attribute, upper limit 2, attribute, lower limit 1, attribute, lower limit 2, attribute can be defined, and attributes are interlock signal, alarm occurrence, buzzer sound,
A reset or the like can be defined, and indicates an operation event when the value goes out of an appropriate range. Thereby, quick notification to the user and the safety performance of the device are improved. These are the same as those described in the first embodiment, and a description thereof will be omitted.

FIG. 25 shows each zone current history graph of the host controller. The upper limit 1, the upper limit 2, the lower limit 1, and the lower limit 2 during the current detection event are displayed, the current data is displayed in real time including the past history, and it is possible to silently check whether there is any abnormality.

Hereinafter, the processing operation according to the second embodiment will be described with reference to FIGS. FIG. 26 is a flowchart showing a switching monitoring process to a current detection event performed by the host controller, and corresponds to FIGS. 12 and 13 of the first embodiment. First, step S12
In step S1, it is determined whether or not the current time is the start time of the current detection event.
The fixed heater output value control is started, and the temperature controller is notified that the current detection mode is set. With this notice,
The processing of FIG. 27 described later is started by interruption. In step S123, the current detection event in-progress flag is set to “1”, and the process ends.

On the other hand, in step S121, if it is not the start time of the current detection event, step S12
Proceeding to 4, it is determined whether or not it is the end time of the current detection event. If it is the end time, the process proceeds to step S125 to notify the temperature controller that the fixed heater output value control has been completed and the current detection mode is to be stopped. In step S126,
The current detection event in-progress flag is set to “0”.

FIG. 27 is a flowchart showing the interrupt processing of the temperature controller when the notification in the processing of FIG. 26 is received from the upper controller. First, step S1
At 31, it is determined whether or not the message is about the start of the fixed heater output control and the start of the current detection mode. If the result is affirmative, the process proceeds to step S132, where the process is shown in FIG. The fixed heater output value control start and the current detection mode start processing are performed.

On the other hand, in the case of a negative result in step S131, it is determined in step S133 whether or not the message is the end of the fixed heater output value control and the end of the current detection mode. If the result is affirmative, in step S134, the fixed heater output value control end and the current detection mode end processing shown in FIG. 28B are performed.
If the determination in step S133 is negative, the process ends.

FIG. 28A shows step S132 in FIG.
3 is a flowchart showing the processing of FIG. First, in step S141, the fixed heater output value control flag is set to "1", and in step S142, the fixed heater output value of each zone is set in a table. Then, in step S143, the current detection mode flag is set to “1”, and the process ends.

FIG. 28B is a flowchart showing step S134 in FIG.
3 is a flowchart showing the processing of FIG. First, in step S151, the fixed heater output value control flag is set to "0", and in step S152, the fixed heater output value of each zone is set to 0% in the table. Then, in step S153, the current detection mode flag is set to “0”, and the process ends.

FIG. 29 is a main flowchart showing the main processing of the temperature controller. First, in order to initialize the operation start, the fixed heater output value control flag is set to 0 in step S161, and in step S162,
The fixed heater output value of 0% for each zone is set in the table, and in step S163, the current detection mode flag is set to “0”.

In step S164, it is determined whether the fixed heater output value control flag is "1". If it is "1", in step S165, a thyristor gate pulse corresponding to the fixed heater output value set in the table is set. Output a signal. Then, in step S166,
It is determined whether or not the current detection mode flag is “1”. If the current detection mode flag is “1”, in step S167, the current is detected and the detected current value is notified to the host controller. The notified current value is received in a process shown in FIG. 30 described later. After the process of step S167, or when the current detection mode flag is not “1” in step S166, the process proceeds to step S168, and temperature detection and notification of the detected temperature to the upper controller are performed. This temperature is used as a monitor temperature for normal temperature control of the reaction chamber.

On the other hand, if it is determined in step S164 that the control flag is not "1", the process proceeds to step S1.
At 69, a control operation (PID operation) is performed to calculate a heater output value, and at step S170, a thyristor gate pulse signal corresponding to the heater output value of the control operation result is output, and the process proceeds to step S166. Note that these processes include control in normal wafer processing.

FIG. 30 is a flowchart showing processing for receiving a message from the temperature controller in the host controller.
If it is determined in step S171 that the received message is temperature, in step S172, the received temperature value of each zone is set in the temperature table. After step S172, or when it is determined in step S171 that the received message is not temperature, step S17
At 3, it is determined whether the received message is a current. If the received message is determined to be current, step S1
At 74, the received current value of each zone is set in the current table, and the process ends. If the received message is not determined to be a current, the process is terminated.

FIG. 31 shows a main flowchart of the host controller. As a main operation of the host controller, first, for initialization, in step S181,
Set the current detection event flag to 0. Hereinafter, steps S182 to S185 are a permanent loop routine that is repeated until the power is turned off.

First, in step S182, FIG.
Perform the event switching monitoring process shown in FIG.
In 183, it is determined whether or not the current detection event in-progress flag is “1”. If the flag is “1”, a current detection check process is performed in step S184. This processing will be described later with reference to FIG.
Then, in step S185, a process of storing (storing) the obtained current value as history data is performed.

FIG. 32 is a subroutine flowchart showing a current detection check process (the process of step S184 in FIG. 31) performed by the host controller. First,
In step S191, it is determined whether or not the current detection event in-progress flag is “1”. If the flag is “1”, in step S192, the temperature in the temperature table is referred to.
The temperature zone is searched to check the content of the condition corresponding to the temperature zone in the current alarm condition table.

Then, steps S193 to S1
At step 96, an abnormal content (attribute) handling process is performed. First, in step S193, it is determined whether or not the current value in the current table is equal to or more than the upper limit 1. If not, it is determined in step S194 whether or not the current value in the current table is equal to or more than the upper limit 2. Is determined. If the current value is not equal to or greater than the upper limit 2, the process proceeds to step S195, and it is determined whether the current value in the current table is equal to or greater than the lower limit 1. If not, the process proceeds to step S196 to determine whether the current value is equal to or greater than the lower limit 2. Is determined. When the determination result of step S193, step S194, or step S196 is affirmative, or after the process of step S196, it is determined that there is a serious or mild abnormality, and the process proceeds to step S197. On the other hand, if the result of the determination in step S195 is affirmative (if it is smaller than the upper limit 2 and equal to or larger than the lower limit 1), it is determined to be normal, and the process ends without step S197.

In step S197, the four pattern determination results determined in steps S193 to S196 (when the upper limit is 1 or more (short circuit), when the upper pattern is smaller than the upper limit 1 and 2 or more (short circuit prediction), Depending on the case where the value is smaller than the lower limit 2 (disconnection prediction) and the case where the value is smaller than or equal to the lower limit 2 (disconnection), processing is performed on the predetermined attribute determined for each.

As described above, for example, as described above, the upper limit of 1 or more (short circuit) and the lower limit of 2 or less (disconnection) are severe abnormalities. In the above cases (disconnection prediction), a slight abnormality is set, and a lower limit of 1 or more is set to normal, which is smaller than the upper limit 2 and an interlock signal, an alarm, a buzzer sounds, a reset, an error event jump, etc. are appropriately applied in the case of an abnormality. And an operation event when the value is out of the appropriate range is indicated.

As described above, in the second embodiment, in the process processing, the current detection event is provided in the standby state so as not to affect the wafer process processing, and the overcurrent prevention and the heater disconnection detection are performed. Can be. At this time, the boat has not been inserted into the reaction tube,
In addition, since the overcurrent (heater disconnection) and the heater disconnection detection time are shorter than the wafer transfer time, the entire sequence time is not extended.

The temperature controller performs a normal control operation when the current detection event is not in progress. However, the temperature controller has a feature that control is performed using a fixed heater output value during the current detection event. Except during the detection event,
It has a mechanism that allows only temperature data to be monitored, thereby improving performance.

It is to be noted that, at a predetermined stable process temperature such as 500 ° C. or 600 ° C., the change with time of the heater current value is recorded, and it is possible to detect a case where the heater current value gradually fluctuates. The disconnection can be predicted from the fluctuation.

[0109]

As is apparent from the above description, according to the present invention, in the standby state before the start of the substrate processing process in which the substrate has not yet been carried into the reaction chamber, it is possible to detect a heater abnormality in the reaction chamber. Since the heater abnormality detection step is provided, it is possible to provide a heater abnormality detection method for a semiconductor manufacturing apparatus that can perform heater disconnection prediction, disconnection detection, and overcurrent prevention at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration according to a first embodiment.

FIG. 2 is a block diagram illustrating details of a temperature controller according to the first embodiment.

FIG. 3 is a block diagram showing details of a host controller.

FIG. 4 is a time chart showing a conventional process processing sequence.

FIG. 5 is a time chart showing a process processing sequence of the present invention.

FIG. 6 is a diagram showing a temperature alarm condition table T1.

FIG. 7 is an I value history graph corresponding to a temperature alarm condition table T1.

FIG. 8 is a diagram showing a temperature alarm condition table T2.

FIG. 9 is a temperature history graph corresponding to a temperature alarm condition table T2 (in a normal state).

FIG. 10 is a temperature history graph corresponding to a temperature alarm condition table T2 (when abnormal).

FIG. 11 is an explanatory diagram of a temperature history corresponding to a temperature alarm condition table T2 for one zone.

FIG. 12 is a flowchart of an event switching function process of the upper controller.

FIG. 13 is a detailed flowchart of an event switching function process of a host controller.

FIG. 14 is a detailed flowchart of an event switching function process of a host controller.

FIG. 15 is a flowchart of a temperature controller processing interrupt.

FIG. 16 is a flowchart of a temperature controller processing subroutine.

FIG. 17 is a temperature controller processing main flowchart.

FIG. 18 is a flowchart of a host controller message reception process.

FIG. 19 is a flowchart of a main controller main process.

FIG. 20 is a flowchart of a higher-order controller subroutine process.

FIG. 21 is a flowchart of a higher-level controller subroutine process.

FIG. 22 is a block diagram showing an overall configuration according to the second embodiment.

FIG. 23 is a block diagram illustrating details of a temperature controller according to the second embodiment.

FIG. 24 is a current alarm condition table.

FIG. 25 is a graph of each zone current history.

FIG. 26 is a flowchart of an event switching function process of the upper controller.

FIG. 27 is a temperature controller interrupt flowchart.

FIG. 28 is a flowchart of a temperature controller processing subroutine.

FIG. 29 is a main flowchart of a temperature controller process.

FIG. 30 is a flowchart of a host controller message reception process.

FIG. 31 is a flowchart of a main controller main process.

FIG. 32 is a flowchart of a higher-level controller subroutine process.

FIG. 33 is a block diagram showing an overall configuration of a conventional semiconductor manufacturing apparatus.

[Explanation of symbols]

 1-4 thermocouple 7 wafer 8 reaction tube 11-14 heating unit (heater) 19-22 thyristor 23 breaker 25A, 25B temperature controller 26A, 26B host controller 27A-30A current sensor

 ──────────────────────────────────────────────────の Continued on front page (72) Inventor Kazuo Tanaka 3-14-20 Higashinakano, Nakano-ku, Tokyo Kokusai Electric Co., Ltd. (72) Inventor Kazuhiro Yokogawa 3-14-20 Higashinakano, Nakano-ku, Tokyo Kokusai Electric F term in the company (reference) 5F045 BB08 DP19 EC02 EK22 GB01 GB15

Claims (13)

[Claims] In a standby state before a substrate processing process in which a substrate has not yet been carried into a reaction chamber, a heater abnormality detection step for detecting a heater abnormality in the reaction chamber is provided. Method. 2. The method according to claim 1, wherein the standby state is a state in which a wafer is transferred from a wafer cassette to a wafer boat. 3. The heater abnormality of a semiconductor manufacturing apparatus according to claim 1, wherein the heater abnormality detection step is a step of judging whether or not an I output value in the PID control of the reaction chamber temperature is appropriate. Detection method. 4. The method according to claim 1, wherein the heater abnormality detecting step varies a heater output value and determines abnormality based on a temperature variation in the reaction chamber. . 5. The method according to claim 4, wherein the temperature control is performed so that the temperature in the reaction chamber returns to the state before the change during the standby state after the temperature change. 6. The heater abnormality detecting method for a semiconductor manufacturing apparatus according to claim 4, wherein the determination in the heater abnormality detecting step is performed based on a time until the temperature fluctuation in the reaction chamber reaches a predetermined value. . 7. The method according to claim 6, wherein if the time required to reach the predetermined value is longer than a reference value, it is determined that the heater is disconnected. 8. The method according to claim 6, wherein if the time required to reach the predetermined value is shorter than a reference value, it is determined that the heater is short-circuited. 9. A heater abnormality detecting method for a semiconductor manufacturing apparatus using the heater abnormality detecting method according to claim 1 for an apparatus having a plurality of zone heaters for any one of the zones. . 10. The heater abnormality detection method for a semiconductor manufacturing apparatus according to claim 1, wherein the heater abnormality detection step determines the presence or absence of an abnormality based on a current value flowing through the heater. 11. The method according to claim 10, wherein when the current value is smaller than a reference value, it is determined that the heater is disconnected. 12. If the current value is larger than a reference value, it is determined that the heater is short-circuited.
A method for detecting a heater abnormality in a semiconductor manufacturing apparatus as described in the above. 13. The apparatus according to claim 3, wherein a plurality of reference values of the detection value used for determining the presence / absence of the abnormality in the heater are set in accordance with a temperature in a standby state. Heater abnormality detection method for a semiconductor manufacturing apparatus.