JP2009076531A - Method of judging deterioration of electric heat wire of semiconductor manufacturing apparatus, and semiconductor manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of judging deterioration of an electric heat wire of a semiconductor manufacturing apparatus capable of preventing failure of treated substrates owing to malfunction of a heater by judging a heater replacing time while using a simple configuration, and to provide a semiconductor manufacturing apparatus. <P>SOLUTION: A vertical diffusion furnace has a cylindrical heater 11 inside a casing. Electric heat wires 24A-24D are provided on blocks 20A-20D of the cylindrical heater 11, respectively. For example, an integrated current values to be supplied to an electric heat wire 24D to maintain a U block 20D at a predetermined temperature (e.g. 800°C) only for a predetermined time is stored as a first integrated current value. Also, when the U block 20D is maintained at a predetermined temperature only for a predetermined time, a first total current value of the integrated current values to be supplied to the electric heat wire 24D so deteriorated as to be replaced is previously obtained. As a result of comparison of the first total current value with the first integrated current value, and if the first integrated current value is larger than the first total current value, it is judged that the electric heat wire 24D is deteriorated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a method for determining deterioration of a heating wire of a semiconductor manufacturing apparatus and a semiconductor manufacturing apparatus.

2. Description of the Related Art Conventionally, there is a heat treatment apparatus as one of semiconductor manufacturing apparatuses used in a manufacturing process of a semiconductor wafer or the like (substrate to be processed) that forms an integrated circuit including semiconductor elements. The heat treatment apparatus is an apparatus that performs a predetermined process on a substrate to be processed by setting the substrate to be processed stored in a processing chamber inside the substrate to a predetermined high temperature. Examples of the process performed on the substrate to be processed by the heat treatment apparatus include an annealing process, a film forming process such as a thin film, and a diffusion process for diffusing impurities.

The heat treatment apparatus generates heat from a heater (heating wire) disposed around the processing chamber to raise the temperature of the processing chamber in which the substrate to be processed is stored to a target high temperature. By the way, when the heating wire is used, it deteriorates due to a secular change accompanying the use. The deteriorated heating wire causes problems such as a decrease in the amount of generated heat and disconnection, and the problems do not make it possible to suitably set the temperature of the processing chamber to a target high temperature. If a defect in the heating wire, particularly disconnection, occurs during the processing of the substrate to be processed, the temperature inside the processing chamber cannot be increased, and there is a great possibility that the substrate to be processed is defective.

Therefore, in order to prevent the substrate to be processed from being defective due to the disconnection of the heater (heating wire), a method has been proposed in which the heater (heating wire) can be suitably predicted and the heater can be replaced if necessary. (Patent Document 1).

In Patent Document 1, a power feedback unit controls a power adjustment thyristor circuit that supplies power from an AC power source to a heater. More specifically, the power feedback unit passes through the power adjustment thyristor circuit based on the measured current and voltage supplied to the heater and the temperature control signal corresponding to the measured temperature of the heater input from the temperature control unit. The power supplied to the heater is feedback controlled. The temperature control unit has a disconnection prediction function. The disconnection prediction function calculates the logical heater resistance value from the measured temperature and resistance temperature coefficient, calculates the actual heater resistance value from the measured current and measured voltage sent from the power feedback unit, and calculates the calculated logical heater resistance value. Based on the actual change rate of the heater resistance value, the possibility of the heater disconnection is determined.
JP 2006-85907 A

However, Patent Document 1 requires measurement of current, voltage, and temperature in order to determine the possibility of heater disconnection, and also requires information specific to the heating wire such as a resistance temperature coefficient. The system configuration for judging was complicated.

The present invention has been made to solve the above problems, and its object is to determine a heater replacement time with a simple configuration and prevent a substrate to be processed from being defective due to a heater failure. An object of the present invention is to provide a method for determining deterioration of a heating wire of a semiconductor manufacturing apparatus and a semiconductor manufacturing apparatus.

A method for determining deterioration of a heating wire of a semiconductor manufacturing apparatus according to the present invention is a method of determining deterioration of a heating wire of a semiconductor manufacturing device having a heater provided with a heating wire, wherein the heater is heated by the heat of the heating wire supplied with a current. When the internal temperature is controlled to a predetermined temperature, the calculated value calculated based on the current value of the current supplied to the heating wire is a deterioration value as a value indicating the deterioration of the heating wire obtained in advance. In comparison, the heating wire is determined to be deteriorated based on a comparison between the calculated value and the deterioration value.

According to the method for determining the deterioration of a heating wire of a semiconductor manufacturing apparatus according to the present invention, it is possible to determine the deterioration of the heating wire based on a comparison between a calculated value calculated based on a current value supplied to the heating wire and a deterioration value. Therefore, it is possible to know the deterioration of the heating wire, for which the determination of the deterioration has not been easy, before the trouble due to the deterioration occurs in the heating wire. As a result, it is possible to prevent the substrate to be processed from being defective due to the defect caused by the deterioration in the heating wire.

In addition, if a value indicating a heating wire that has deteriorated to such an extent that replacement is necessary is used as the deterioration value, it is possible to know the replacement time of the deteriorated heating wire.
In the method for determining deterioration of a heating wire of this semiconductor manufacturing apparatus, the calculated value is a first integrated current value obtained by integrating the current value supplied to the heating wire within a predetermined measurement time, and the deterioration value is The first total current value obtained by integrating the current values supplied within the measurement time when the heating wire is deteriorated, and the calculated value is compared with the deterioration value, and the calculated value is the deterioration value. If it is larger, it is preferable to determine that the heating wire has deteriorated.

According to the heating wire deterioration determining method of this semiconductor manufacturing apparatus, the heating wire deterioration is determined based on the first integrated current value within a predetermined measurement time. Therefore, when it is desired to determine the deterioration, it is possible to easily determine the deterioration of the heating wire simply by securing a predetermined measurement time.

In this method for determining the deterioration of a heating wire of a semiconductor manufacturing apparatus, the calculated value is a second integrated current value obtained by integrating the current values that have been supplied since the start of use of the heating wire. The value is a second total current value that is an integration of current values that can be passed through the heating wire until it deteriorates after the heating wire is used, and the calculated value is compared with the deterioration value. Then, when the calculated value is larger than the deterioration value, it may be determined that the heating wire is deteriorated.

According to the heating wire deterioration determination method of this semiconductor manufacturing apparatus, the calculated value is easy because it is an integrated current value supplied to the heating wire. Further, since the integrated current value is a value obtained by integrating all the current values that have flowed through the heating wire, it is possible to suitably determine the deterioration of the heating wire due to the current flowing.

In this method for determining deterioration of a heating wire of a semiconductor manufacturing apparatus, the calculated value is a summation of current values that can be passed through the heating wire until the heating wire is deteriorated after starting to use. A differential current value is calculated from the difference between the current value and the second integrated current value obtained by integrating the current value supplied so far after the use of the heating wire is started, and the second integrated current value is calculated. Calculate the average current value per day divided by the number of days of use of the heating wire so far, the remaining number of days until the heating wire is obtained by dividing the difference current value by the average current value, The deterioration value is the number of days for determining deterioration of the heating wire with respect to the remaining number of days. When the calculated value is compared with the deterioration value, the calculated value is smaller than the deterioration value. It is also preferable to determine that the heating wire has deteriorated.

According to the method for determining deterioration of a heating wire of this semiconductor manufacturing apparatus, the period until the heating wire is deteriorated can be calculated as the number of remaining days corresponding to the use state of the heating wire. As a result, it is possible to easily know the time until the heating wire is deteriorated as the remaining number of days corresponding to the usage state of the heating wire.

The heating wire deterioration determining method of the semiconductor manufacturing apparatus may determine the heating wire deterioration when the temperature inside the heater is controlled to a constant temperature.
According to this method for determining the deterioration of a heating wire of a semiconductor manufacturing apparatus, since the determination of deterioration is made when the temperature inside the heater is controlled to a constant temperature, the measurement that requires temperature rise or fall of the heater temperature is required. Compared to the above, the measurement conditions are simple and the number of measurement opportunities can be increased. Moreover, the troublesomeness of raising or lowering the temperature of the heater can be reduced.

The semiconductor manufacturing apparatus of the present invention is provided with a heat insulating cylinder provided in a heater, a heating wire spirally disposed along an inner surface of the heat insulating cylinder, and an inner side of the heating wire. An inner tube that can isolate the substrate to be processed from the outside air, a current sensor that measures a current supplied to the heating wire to determine deterioration of the heating wire, and a heating sensor When the temperature inside the heater is controlled to a predetermined temperature by heat, a calculated value calculated based on the current value of the current supplied to the heating wire is a value indicating deterioration of the heating wire obtained in advance. And a deterioration determination means for determining that the heating wire is deteriorated based on a comparison between the calculated value and the deterioration value.

According to the semiconductor manufacturing apparatus of the present invention, it is possible to determine the deterioration of the heating wire based on the comparison between the calculated value and the deterioration value. Therefore, it is arranged between the heat insulation cylinder and the inner pipe, and for the heating wire that cannot usually be easily judged as to deterioration, know the time of replacement due to deterioration before the failure due to deterioration occurs in the heating wire. be able to. As a result, it is possible to prevent the substrate to be processed from being defective due to the defect caused by the deterioration in the heating wire.

In addition, if a value indicating a heating wire that has deteriorated to such an extent that replacement is necessary is used as the deterioration value, it is possible to know the replacement time of the deteriorated heating wire.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view showing a cross-sectional structure of a vertical diffusion furnace 1 as a semiconductor manufacturing apparatus.
As shown in FIG. 1, the vertical diffusion furnace 1 is a device for heat-treating a substrate to be processed, and has a housing 10. Inside the housing 10, a cylindrical heater 11 and an inner tube 12 that is concentric with the cylindrical heater 11 provided inside the cylindrical heater 11 are provided. A boat 13 on which a plurality of substrates to be processed (workpieces) W are mounted is disposed inside the inner tube 12.

The housing 10 has a door (not shown) used for maintenance and the like. When the door is opened, the outer surface 11A of the cylindrical heater 11 disposed inside the housing 10 is exposed from the outside of the housing 10. You can see it.

A heater support portion 10A is formed to extend on the inner side surface of the housing 10, and the heater support portion 10A.
A hole 10 </ b> B having a size substantially the same as the outer diameter of the inner tube 12 is formed through. The heater support portion 10A is provided between the top plate 10C of the housing 10 so that the cylindrical heater 11 can be disposed, and the upper surface of the heater support portion 10A is configured to be substantially horizontal. .

An annular heater base 14 having substantially the same size as the bottom surface of the cylindrical heater 11 is fixed on the upper surface of the heater support portion 10A. The bottom surface of the cylindrical heater 11 is supported and fixed on the upper surface of the heater base 14. Further, a heat insulating material 14 </ b> A that covers the upper surface opening of the cylindrical heater 11 is fixed to the upper surface of the cylindrical heater 11.

An annular furnace port flange 15 is fitted and fixed to the inner peripheral surface of a hole 10B formed through the heater support 10A.
The upper portion of the furnace port flange 15 extends upward from the upper surface of the heater support portion 10 </ b> A, and is formed in an annular shape having substantially the same size as the diameter of the inner tube 12. The bottom of the inner tube 12 is airtightly fixed to the top of the furnace port flange 15. Further, the inner diameter of the furnace port flange 15 is formed to be approximately the same as the inner diameter of the inner tube 12.

A boat 13 is detachably disposed in the inner tube 12 (processing chamber 12A). The boat 13 is configured to mount a plurality of workpieces W between a top plate 13B and a bottom plate 13C supported by the frame 13A.

The boat 13 is mounted and fixed to the seal cap 16 via a heat insulating cap 17.
The upper surface of the heat insulating cap 17 is configured to detachably mount and fix the bottom plate 13C of the boat 13. The lower surface of the heat insulating cap 17 is fixed to the seal cap 16.

The seal cap 16 is formed in such a size that the lower part of the furnace port flange 15 can be covered in a lid shape from below, and is moved up and down by a lifting device (not shown) so as to move the furnace port flange 1.
It is comprised so that contact / separation is possible with respect to the lower part of 5. FIG. The peripheral portion of the upper surface of the seal cap 16 is in contact with the lower portion of the furnace port flange 15, and when it comes into contact with the lower surface of the furnace port flange 15, the space between the furnace port flange 15 is hermetically sealed. That is, the inside of the inner tube 12 (the processing chamber 12A) is hermetically sealed from the outside when the seal cap 16 comes into contact with the furnace port flange 15.

That is, the boat 13 is placed and fixed on the upper surface of the heat insulating cap 17 when the seal cap 16 moves down most, and is inserted into the inner tube 12 by the upward movement of the seal cap 16 and hermetically sealed in the processing chamber 12A. It has come to be. Further, the boat 13 is detached from the inner tube 12 by the downward movement of the seal cap 16 from the state hermetically sealed in the processing chamber 12A, and is removed from the upper surface of the heat insulating cap 17 when the seal cap 16 is moved down most. Be able to.

A gas introduction pipe 18 and an exhaust pipe 19 from the outside of the inner pipe 12 are communicated with the processing chamber 12A. The gas introduction pipe 18 communicates from the outside of the furnace port flange 15 to the upper part of the processing chamber 12A. The exhaust pipe 19 communicates with the outside of the furnace port flange 15 from the processing chamber 12A.

With the above configuration, the vertical diffusion furnace 1 transfers each workpiece W mounted on the boat 13 to the processing chamber 12A.
And heat-treated with the cylindrical heater 11. The vertical diffusion furnace 1 introduces gas from the gas introduction pipe 18 into the sealed processing chamber 12A and exhausts the gas in the processing chamber 12A to the exhaust pipe 1.
9 can be discharged.

As shown in FIGS. 2 and 3, the cylindrical heater 11 has a heat insulating layer 21 as a cylindrical heat insulating cylinder made of a heat insulating material. On the inner surface of the heat insulating layer 21, a plurality of heating wire holding members 22 extending in the vertical direction on the inner surface are arranged and fixed at equal angular intervals. A plurality of holding holes 23 are formed through the heating wire holding member 22 at predetermined intervals in the vertical direction.

The cylindrical heater 11 is divided into four blocks that are continuous in the vertical direction, and an L (Lower) block 20A and a CL (Center Lower) block 20B are sequentially arranged from the bottom.
, A CU (Center Upper) block 20C and a U (Upper) block 20D. That is, the L block 20A is assigned to the lowermost part of the cylindrical heater 11, and the CL block 20B is assigned to the lower center of the cylindrical heater 11 adjacent to the upper side of the L block 20A. Further, the CU block 20C is composed of the CL block 2
Assigned to the upper center of the cylindrical heater 11 adjacent to the upper side of 0B,
D is assigned to the uppermost part of the cylindrical heater 11 adjacent to the upper side of the CU block 20C.

On the inner side surface of the L block 20 </ b> A, a single lower heating wire 24 </ b> A is spirally arranged by inserting each holding hole 23 formed in the heating wire holding member 22. Lower heating wire 24A
Is arranged between the lower part and the upper part of the L block 20A by inserting and holding the holding holes 23 of the heating wire holding members 22 in a predetermined order.

The upper end and the lower end of the lower heating wire 24A are electrically connected to the base ends of separate terminals 25A, respectively. Each terminal 25A has a heat insulating layer 2 at the upper and lower portions of the L block 20A, respectively.
1 and the end of each terminal 25 </ b> A is extended to the outside of the heat insulating layer 21. That is, power can be supplied from the outside to each terminal 25A.
When electric power is supplied between them, electric power is supplied to the lower heating wire 24A, and the electric heating wire 24 is supplied by the electric power.
A generates heat.

The L block 20A is provided with a lower temperature sensor 26A and a second temperature sensor 27A. Each temperature sensor 26A, 27A is formed in a bar shape,
A thermocouple for measuring the temperature is provided at each tip. And each temperature sensor 26A, 27A is penetrated and supported from the outside of the cylindrical heater 11 to the inside of the cylindrical heater 11,
Each tip portion is arranged in the vicinity of the inner tube 12 so that the temperature in the vicinity of the inner tube 12 can be measured. The second temperature sensor 27A shuts off the power supplied between the terminals 25A and forcibly cuts the power supply to the lower heating wire 24A when the measured temperature is equal to or higher than a predetermined temperature. It has become.

On the inner surface of the CL block 20B, one central lower heating wire 24B is provided with a heating wire holding member 22.
Each of the holding holes 23 formed in is inserted into a spiral shape. The central lower heating wire 24B is disposed between the lower portion and the upper portion of the CL block 20B by inserting and holding the holding holes 23 of the heating wire holding members 22 in a predetermined order.

The upper end and the lower end of the central lower heating wire 24B are electrically connected to the base ends of separate terminals 25B, respectively. Each terminal 25B is penetrated and supported by the heat insulating layer 21 at the upper part and the lower part of the CL block 20B, and the tip of each terminal 25B is extended to the outside of the heat insulating layer 21. That is, power can be supplied from the outside to each terminal 25B. When power is supplied between the terminals 25B, power is supplied to the central lower heating wire 24B, and the power heating wire 24B is supplied by the power. It is supposed to generate heat.

The CL block 20B includes a central lower temperature sensor 26B and a second temperature sensor 27B.
Are provided. Each of the temperature sensors 26B and 27B is formed in a bar shape, and a thermocouple for measuring the temperature is provided at each tip. And each temperature sensor 26B, 27B is penetrated and supported from the exterior of the cylindrical heater 11 to the inside of the cylindrical heater 11, and each tip part is arrange | positioned in the vicinity of the inner tube 12, and the temperature of the vicinity of the inner tube 12 is provided. Can be measured. The second temperature sensor 27B cuts off the power supplied between the terminals 25B and forcibly cuts off the power supply to the central lower heating wire 24B when the measured temperature becomes a predetermined temperature or higher. It is like that.

On the inner surface of the CU block 20C, one central upper heating wire 24C is connected to the heating wire holding member 22.
Each of the holding holes 23 formed in is inserted into a spiral shape. The central upper heating wire 24C is disposed between the lower part and the upper part of the CU block 20C by inserting and holding the holding holes 23 of the heating wire holding members 22 in a predetermined order.

The upper end and the lower end of the central upper heating wire 24C are electrically connected to the base ends of separate terminals 25C, respectively. Each terminal 25C is penetrated and supported by the heat insulating layer 21 at the upper and lower portions of the CU block 20C, and the tip of each terminal 25C is extended to the outside of the heat insulating layer 21. That is, power can be supplied to each terminal 25C from the outside. When power is supplied between the terminals 25C, power is supplied to the central upper heating wire 24C, and the electric heating wire 24C is supplied by the power. It is supposed to generate heat.

The CU block 20C includes a central upper temperature sensor 26C and a second temperature sensor 27C.
Are provided. Each of the temperature sensors 26C and 27C is formed in a rod shape, and a thermocouple for measuring the temperature is provided at each tip portion. And each temperature sensor 26C, 27C is penetrated and supported from the outside of the cylindrical heater 11 to the inside of the cylindrical heater 11, and the temperature of the vicinity of the inner tube 12 is set by arranging the respective tip portions in the vicinity of the inner tube 12. Can be measured. The second temperature sensor 27C shuts off the power supplied between the terminals 25C and forcibly cuts the power supply to the central upper heating wire 24C when the measured temperature is equal to or higher than a predetermined temperature. It is like that.

On the inner side surface of the U block 20 </ b> D, a single upper heating wire 24 </ b> D is spirally arranged by passing through each holding hole 23 formed in the heating wire holding member 22. Upper heating wire 24D
Are arranged between the lower part and the upper part of the U block 20D by inserting and holding the holding holes 23 of the heating wire holding members 22 in a predetermined order.

The upper end and the lower end of the upper heating wire 24D are electrically connected to the base ends of separate terminals 25D, respectively. Each terminal 25D has a heat insulating layer 2 at the upper and lower portions of the U block 20D, respectively.
1 and the end of each terminal 25 </ b> D is extended to the outside of the heat insulating layer 21. That is, power can be supplied from the outside to each terminal 25D.
When electric power is supplied between them, electric power is supplied to the upper heating wire 24D, and the electric heating wire 24 is supplied by the electric power.
D generates heat.

The U block 20D is provided with an upper temperature sensor 26D and a second temperature sensor 27D. Each temperature sensor 26D, 27D is formed in a bar shape,
A thermocouple for measuring the temperature is provided at each tip. And each temperature sensor 26D, 27D is penetrated and supported from the outside of the cylindrical heater 11 to the inside of the cylindrical heater 11,
Each tip portion is arranged in the vicinity of the inner tube 12 so that the temperature in the vicinity of the inner tube 12 can be measured. The second temperature sensor 27D shuts off the power supplied between the terminals 25D and forcibly cuts off the power supply to the upper heating wire 24D when the measured temperature is equal to or higher than a predetermined temperature. It has become.

In the present embodiment, each of the heating wires 24A, 24B, 24C, and 24D is a heating wire that generates heat when supplied with electric power, for example, a nichrome wire, and is formed in an electric wire shape having a thickness of 20 mm.

Next, the electrical configuration of the vertical diffusion furnace 1 configured as described above will be described with reference to FIG.
As shown in FIG. 4, the vertical diffusion furnace 1 includes a control device 30 as a deterioration determination unit.

The control device 30 includes a CPU (Central Processing Unit), ROM, and RAM. The CPU of the control device 30 executes various processes according to various data and various control programs stored in the ROM and RAM.

In the present embodiment, the CPU calculates the upper heating wire 24D from the temperature change amount per unit time of the U block 20D due to the heat generated by the upper heating wire 24D based on the programs and various data stored in the ROM and RAM. A deterioration determination process for determining the deterioration of the image is performed. CP
Similarly to the case of the upper heating wire 24D, U represents each heating wire 24A, 24B from the amount of temperature change per unit time of each block 20A, 20B, 20C corresponding to the heat generated by each heating wire 24A, 24B, 24C. , 24C for determining deterioration, respectively.
Further, the RAM is provided with addresses for deterioration state flags for recording the deterioration states of the heating wires 24A, 24B, 24C, and 24D, respectively.

The control device 30 is electrically connected to the upper temperature sensor 26D. The control device 30
From the temperature signal 26Dt inputted from the upper temperature sensor 26D, the temperature T of the U block 20D
m4 is calculated.

The control device 30 is electrically connected to the central upper temperature sensor 26C. Control device 30
Is obtained from the temperature signal 26Ct input from the center upper temperature sensor 26C.
The temperature Tm3 of C is calculated.

The control device 30 is electrically connected to the center lower temperature sensor 26B. Control device 30
From the temperature signal 26Bt input from the center lower temperature sensor 26B, the CL block 20
The temperature Tm2 of B is calculated.

The control device 30 is electrically connected to the lower temperature sensor 26A. The control device 30
From the temperature signal 26At input from the lower temperature sensor 26A, the temperature T of the L block 20A
m1 is calculated.

The external power supply 29 is electrically connected to the upper heating wire drive circuit 31 and supplies a predetermined power PW to the upper heating wire drive circuit 31.
The control device 30 is electrically connected to the upper heating wire drive circuit 31. The upper heating wire driving circuit 31 supplies the driving current 31D generated from the power PW supplied from the external power source 29 to the upper heating wire 24D based on the upper heating wire control signal 31C input from the control device 30 to the same heating power. The drive of the heat wire 24D is controlled.

The external power source 29 is electrically connected to the central upper heating wire drive circuit 32 and supplies a predetermined power PW to the central upper heating wire drive circuit 32.
The control device 30 is electrically connected to the central upper heating wire driving circuit 32. The central upper heating wire driving circuit 32 supplies the driving current 32D generated from the power PW supplied from the external power supply 29 to the central upper heating wire 24C based on the central upper heating wire control signal 32C input from the control device 30. The electric heating wire 24C is driven and controlled.

The external power source 29 is electrically connected to the central lower heating wire driving circuit 33 and supplies a predetermined power PW to the central lower heating wire driving circuit 33.
The control device 30 is electrically connected to the central lower heating wire driving circuit 33. The central lower heating wire driving circuit 33 supplies the driving current 33D generated from the power PW supplied from the external power supply 29 to the central lower heating wire 24B based on the central lower heating wire control signal 33C input from the control device 30. The electric heating wire 24B is driven and controlled.

The external power supply 29 is electrically connected to the lower heating wire drive circuit 34 and supplies predetermined power PW to the lower heating wire drive circuit 34.
The control device 30 is electrically connected to the lower heating wire drive circuit 34. The lower heating wire driving circuit 34 supplies a driving current 34D generated from the power PW supplied from the external power supply 29 to the lower heating wire 24A based on the lower heating wire control signal 34C input from the control device 30 to the lower heating wire 24A. Drive control of the heat wire 24A is performed.

The control device 30 is electrically connected to the upper ammeter 35. The upper ammeter 35 measures the current of the drive current 31D supplied from the upper heating wire drive circuit 31 to the upper heating wire 24D. The control device 30 receives the upper heating wire 24 from the current signal 35C input from the upper ammeter 35.
The current value Ic4 flowing through D is calculated.

The control device 30 is electrically connected to the central upper ammeter 36. Center upper ammeter 36
Is a drive current 32D supplied from the center upper heating wire drive circuit 32 to the center upper heating wire 24C.
Measure the current. The control device 30 has a current signal 36C input from the central upper ammeter 36.
From this, the current value Ic3 flowing through the central upper heating wire 24C is calculated.

The control device 30 is electrically connected to the central lower ammeter 37. Lower center ammeter 37
Is a drive current 33D supplied from the center lower heating wire drive circuit 33 to the center lower heating wire 24B.
Measure the current. The control device 30 has a current signal 37C input from the central lower ammeter 37.
From this, the current value Ic2 flowing through the central lower heating wire 24B is calculated.

The control device 30 is electrically connected to the lower ammeter 38. The lower ammeter 38 measures the current of the drive current 34D supplied from the lower heating wire drive circuit 34 to the lower heating wire 24A. The control device 30 reads the lower heating wire 24 from the current signal 38C input from the lower ammeter 38.
The current value Ic1 flowing through A is calculated.

The control device 30 is electrically connected to the input / output device 39. The control device 30 receives various data DT and the like for the vertical diffusion furnace 1 to heat-treat the workpiece W from the input / output device 39 and stores the data in the RAM. In addition, the control device 30 displays a display signal P indicating various states of the vertical diffusion furnace 1.
S is output to the input / output device 39. The input / output device 39 displays various information on the status indicator 39D based on the input display signal PS. In the present embodiment, the replacement timing of each heating wire 24A, 24B, 24C, 24D is displayed on the status indicator 39D based on the display signal PS.

Next, a method for determining the deterioration of the upper heating wire 24D in the vertical diffusion furnace 1 configured as described above will be described. Note that the deterioration of the lower heating wire 24A, the central lower heating wire 24B, and the central upper heating wire 24C can be determined in the same manner as in the case of the upper heating wire 24D. Only the method of determination will be described, and description of the method of determining deterioration of the lower heating wire 24A, the central lower heating wire 24B, and the central upper heating wire 24C will be omitted.

In general, the upper heating wire 24D with little deterioration such as a new one has a large amount of heat generation per unit power,
On the other hand, it is known that the upper heating wire 24D that has deteriorated has a small amount of heat generation per unit power. That is, when the upper heating wire 24D with little deterioration is used, the U block 20D
The temperature rises with little electric power (current). On the other hand, when the upper heating wire 24D having deteriorated is used, the U block 20D requires a large amount of electric power (current) for temperature rise. Therefore, in the present embodiment, the replacement timing of the upper heating wire 24D is determined from the power (current) required for the temperature rise of the U block 20D.

FIG. 5A shows a change in current (power) supplied to the upper heating wire 24D with little deterioration when the temperature Tm4 of the U block 20D is maintained at a predetermined temperature, for example, 800 degrees. A cumulative amount of electric power (current) supplied to the upper heating wire 24D is shown in a graph 41.

FIG. 5B shows a change in current (power) supplied to the deteriorated upper heating wire 24D when the temperature Tm4 of the U block 20D is similarly maintained at a predetermined temperature, for example, 800 degrees, in a graph 42. A cumulative amount of electric power (current) supplied to the upper heating wire 24D is shown in a graph 43.

More specifically, when the temperature Tm4 of the U block 20D is maintained at a predetermined temperature (800 degrees in FIG. 5), the temperature Tm4 decreases from the predetermined temperature (800 degrees) beyond a predetermined allowable temperature difference range. Then, current control for supplying current to the upper heating wire 24D is performed. On the other hand, when the temperature Tm4 rises from a predetermined temperature (800 degrees) beyond a predetermined allowable temperature difference range, current control is performed in which the current of the upper heating wire 24D is cut off. That is, the upper heating wire 24
As shown in graphs 40 and 42, the current supplied to D is controlled such that “0” and a predetermined current value Is are changed in a stepped manner.

At this time, since the upper heating wire 24D with little deterioration has a large amount of heat generation per unit power, the temperature Tm4 of the U block 20D can be maintained at a predetermined temperature if the current of the current value Is is supplied for a short time. . For example, as shown in the graph 40, the time t2 when the current is supplied is shorter than the time t1 when the current is not supplied. As shown in the graph 41, the cumulative power amount at this time has a small increase amount with respect to time.

On the other hand, since the deteriorated upper heating wire 24D generates a small amount of heat per unit power, the current of the current value Is is supplied for a relatively long time in order to maintain the temperature Tm4 of the U block 20D at a predetermined temperature. It is necessary to For example, as shown in the graph 42, the time t4 when the current is supplied is longer than the time t3 when the current is not supplied. As shown in the graph 43, the accumulated power amount at this time increases with time.

Similarly, when the temperature Tm4 of the U block 20D is raised or lowered, the current is supplied to the upper heating wire 24D that has not deteriorated during the time that the current is supplied to the upper heating wire 24D that has deteriorated. It becomes longer with respect to the supplied time.

That is, the upper heating wire 2 at the time of the graph 41 is compared with the upper heating wire 24D at the time of the graph 40 from the comparison of the length of time during which the current of the current value Is is supplied and the supplied cumulative power amount.
It can be seen that the deterioration of 4D is progressing.

Therefore, the processing procedure of the control device 30 for determining the deterioration of the upper heating wire 24D from the amount of current supplied to the upper heating wire 24D will be described with reference to the flowchart shown in FIG.
First, the control device 30 sets the temperature Tm4 of the U block 20D to a predetermined temperature (for example, 800 degrees) and enters an operation for maintaining the temperature at the predetermined temperature, and then starts the first deterioration determination process as shown in FIG. To do. When the first deterioration determination process is started, control device 30 clears the value of first integrated current value Ip1 as a calculated value (step S20).

When the value of the first integrated current value Ip1 is cleared, the control device 30 determines whether or not a predetermined measurement time has elapsed (step S21). The determination of whether the measurement time has passed is C
The timer provided in the PU is determined by starting the measurement operation after the first deterioration determination process is started. If within the measurement time (NO in step S21), the control device 30 measures the drive current 31D supplied to the upper heating wire 24D and calculates the current value Ic4 (step S22). Then, after the calculated current value Ic4 is integrated with the first integrated current value Ip1 (step S23), the process returns to step S21, and the determination after whether or not a predetermined measurement time has elapsed is repeated at a constant cycle.

That is, the control device 30 samples the drive current 31D at a constant period from the start of the first deterioration determination process until the measurement time elapses, and the current value Ic at the time of the sampling.
4 is calculated, and the calculated current value Ic4 at that time is integrated into the first integrated current value Ip1.

On the other hand, when the measurement time has elapsed (YES in step S21), control device 30 determines whether or not first integrated current value Ip1 is greater than deterioration value and deterioration determination threshold value β1 as the first total current value. (Step S24). The degradation determination threshold value β1 is a value obtained in advance in a test based on sampling at the same sampling period as described above, and is supplied to the upper heating wire 24D that has deteriorated to the extent that replacement is necessary. It is a value obtained by integrating current values necessary to maintain the temperature Tm4 of the U block 20D at a predetermined temperature (800 degrees in this case).

When the first integrated current value Ip1 is larger than the degradation determination threshold value β1 (YE in step S24)
S), the control device 30 sets “1” in the deterioration flag (step S25), and adds a signal indicating that the upper heating wire 24D is deteriorated to the display signal PS to input / output device 39.
(Step S26). Then, the control device 30 ends the first deterioration determination process.

On the other hand, when the first integrated current value Ip1 is not larger than the deterioration determination threshold value β1 (step S
The control device 30 sets “0” to the deterioration flag (step S27), and then ends the first deterioration determination process.

With the above configuration, the vertical diffusion furnace 1 knows the replacement time due to deterioration of the upper heating wire 24D before the trouble such as cutting occurs in the upper heating wire 24D by comparing the remaining days α1 with the deterioration determination threshold value β1. be able to.

Next, effects of the present embodiment configured as described above will be described below.
(1) According to the present embodiment, the deterioration of the upper heating wire 24D is determined based on the comparison between the first integrated current value Ip1 and the deterioration determination threshold value β1. Accordingly, it is possible to know the replacement timing of the upper heating wire 24D that cannot be judged visually from the outside or from the inside before the malfunction due to the degradation occurs. . As a result, it was possible to prevent the work W from being defective due to a defect caused by the deterioration in the upper heating wire 24D.

(2) According to the present embodiment, the current value Ic4 within the measurement time is measured and the first deterioration determination process is performed. Therefore, it is possible to determine the deterioration of the upper heating wire 24D by securing the measurement time for measuring the current value Ic4 when it is desired to determine the deterioration of the upper heating wire 24D.

(3) According to the present embodiment, the deterioration determination threshold value β1 is supplied to the upper heating wire 24D that has deteriorated to a degree that requires replacement, and maintains the temperature Tm4 of the U block 20D at 800 degrees per unit time. Therefore, a value obtained by integrating the current values necessary for this purpose was used. Therefore, the deterioration determination threshold value β1 and the first integrated current value Ip1 are compared, and when the first integrated current value Ip1 is larger than the deterioration determination threshold value β1, the replacement timing of the upper heating wire 24D is instructed. be able to.

(4) According to the present embodiment, the temperature Tm4 of the U block 20D is set to a predetermined temperature (for example, 80m).
At 0 degree), the deterioration of the upper heating wire 24D was determined. Therefore, the measurement conditions are simple and the number of measurement opportunities can be increased as compared with the case where temperature increase or decrease is required. Further, when determining the deterioration of the upper heating wire 24D, it is possible to reduce the troublesomeness of raising or lowering the temperature Tm4 of the U block 20D.

In addition, you may change the said embodiment as follows.
In the above embodiment, the cylindrical heater 11 is divided into four blocks in the vertical direction, but may be divided into other than four blocks. Moreover, the cylindrical heater 11 does not need to be divided.

In the embodiment described above, the replacement timing due to deterioration is determined for all the heating wires 24A, 24B, 24C, and 24D, but the replacement timing due to deterioration may be determined for at least some of the heating wires.

In the above embodiment, the deterioration of the upper heating wire 24D is determined based on the first integrated current value Ip1 during the measurement period, but the current that has flowed from the start of use to the upper heating wire 24D so far The deterioration of the upper heating wire 24D may be determined based on the second integrated current value Ip2 that is the integration of the values. In this case, a comparison between the second total current value Imax2 and the second total current value Ip2 obtained from the amount of integrated current that can be passed through the predetermined upper heating wire 24D, for example, the second total current value Imax2 Is larger than the second integrated current value Ip2, the upper heating wire 2
It can be determined that 4D has deteriorated.

Further, in this case, the average current value Id per day is obtained by dividing the second integrated current value Ip2 by the number of days of use of the upper heating wire 24D so far. The second total current value Imax2 and the second
The difference current value ΔI (= Imax2−Ip2) obtained from the difference from the integrated current value Ip2 is divided by the average current value Id, and the remaining days α1 (= ΔI / Id) until the upper heating wire 24D deteriorates. You can also be notified. In addition, the number of days α2 for determining the deterioration of the heating wire obtained in advance
When the remaining number of days α1 is smaller than the number of days α2, the upper heating wire 24D
It is also possible to notify the deterioration of.

In the above embodiment, the deterioration determination of each heating wire 24A, 24B, 24C, 24D of the vertical diffusion furnace 1 is performed, but the deterioration determination of the heating wire is performed by another semiconductor manufacturing apparatus using the heating wire, for example, horizontal diffusion. You may use for a furnace, a thermostat, a washing tank, a drying furnace, or a burn-in furnace.

Sectional drawing which shows the cross-section of the semiconductor manufacturing apparatus in this embodiment. Sectional drawing which shows the cross-section of the cylindrical heater of the semiconductor manufacturing apparatus in this embodiment. The perspective view which shows the perspective structure which made a cross section the part of the cylindrical heater of the semiconductor manufacturing apparatus in this embodiment. The block diagram which shows the electrical structure of the part regarding the cylindrical heater of the semiconductor manufacturing apparatus in this embodiment. It is a graph which shows the example of the electric current supplied to the heating wire of the semiconductor manufacturing apparatus in this embodiment, (a) is a figure which shows the electric current supplied to a new heating wire, (b) is progressing deterioration. The figure which shows the electric current supplied to the heating wire which became the replacement time. The flowchart figure which shows the deterioration determination procedure of the semiconductor manufacturing apparatus in this embodiment.

Explanation of symbols

W: Substrate (work), DT: Data, PS: Display signal, PW: Power, t1, t2
, T3, t4 ... time, 1 ... vertical diffusion furnace, 10 ... housing, 10A ... heater support, 10B ... hole, 10C ... top plate, 11 ... cylindrical heater, 11A ... outer surface, 12 ... inner tube, 12A ... Processing chamber, 1
3 ... Boat, 13A ... Frame, 13B ... Top plate, 13C ... Bottom plate, 14 ... Heater base, 14
A ... heat insulating material, 15 ... furnace port flange, 16 ... seal cap, 17 ... heat insulating cap, 18 ...
Gas introduction pipe, 19 ... exhaust pipe, 20A ... L block, 20B ... CL block, 20C ... CU
Block, 20D ... U block, 21 ... Heat insulation layer, 22 ... Heating wire holding member, 23 ... Holding hole,
24A ... lower heating wire, 24B ... center lower heating wire, 24C ... center upper heating wire, 24D ... upper heating wire, 25A, 25B, 25C, 25D ... terminal, 26A ... lower temperature sensor, 26B ... lower center temperature sensor, 26C ... Center upper temperature sensor, 26D ... Upper temperature sensor, 26At,
26Bt, 26Ct, 26Dt ... temperature signal, 27A, 27B, 27C, 27D ... second temperature sensor, 29 ... external power supply, 30 ... control device, 31 ... upper heating wire drive circuit, 31C ... upper heating wire control signal, 31D, 32D, 33D, 34D ... driving current, 32 ... center upper heating wire drive circuit, 32C ... center upper heating wire control signal, 33 ... center lower heating wire drive circuit, 33C ... center lower heating wire control signal, 34 ... lower heating wire Drive circuit, 34C ... lower heating wire control signal, 35 ...
Upper ammeter, 35C, 36C, 37C, 38C ... current signal, 36 ... middle upper ammeter, 37
... Lower center ammeter, 38 ... Lower ammeter, 39 ... I / O device, 39D ... Status indicator, 40-
43. Graph.

Claims (6)

A method for determining deterioration of a heating wire of a semiconductor manufacturing apparatus having a heater provided with a heating wire,
When the temperature inside the heater is controlled to a predetermined temperature by the heat of the heating wire supplied with current, a calculated value calculated based on the current value of the current supplied to the heating wire is obtained in advance. Compared with a deterioration value as a value indicating the deterioration of the heating wire, it is determined that the heating wire is deteriorated based on a comparison between the calculated value and the deterioration value. Method for judging deterioration of heating wire. In the method for judging deterioration of heating wire of the semiconductor manufacturing apparatus according to claim 1,
The calculated value is a first integrated current value obtained by integrating the current value supplied to the heating wire within a predetermined measurement time,
The deterioration value is a first total current value obtained by integrating current values supplied within the measurement time when the heating wire is deteriorated,
Comparing the calculated value and the deterioration value, and determining that the heating wire is deteriorated when the calculated value is larger than the deterioration value, the deterioration determination of the heating wire of the semiconductor manufacturing apparatus, Method. In the method for judging deterioration of heating wire of the semiconductor manufacturing apparatus according to claim 1,
The calculated value is a second integrated current value obtained by integrating the current values that have been supplied since the start of use of the heating wire,
The deterioration value is a second total current value that is an integration of current values that can be passed through the heating wire until it deteriorates after the heating wire is used.
Comparing the calculated value and the deterioration value, and determining that the heating wire is deteriorated when the calculated value is larger than the deterioration value, the deterioration determination of the heating wire of the semiconductor manufacturing apparatus, Method. In the method for judging deterioration of heating wire of the semiconductor manufacturing apparatus according to claim 1,
The calculated value is a second total current value that is an integration of current values that can be passed through the heating wire until the heating wire is deteriorated after the heating wire is used, and since the heating wire is used. A differential current value is calculated from the difference from the second integrated current value obtained by integrating the current values supplied so far, and the second integrated current value is divided by the number of days of use of the heating wire so far. An average current value per day is calculated and the number of remaining days until the heating wire is obtained by dividing the difference current value by the average current value.
The deterioration value is the number of days for determining deterioration of the heating wire with respect to the remaining days.
Comparing the calculated value and the deterioration value, and determining that the heating wire is deteriorated when the calculated value is smaller than the deterioration value, the deterioration determination of the heating wire of the semiconductor manufacturing apparatus, Method. In the heating wire deterioration determination method of the semiconductor manufacturing apparatus according to any one of claims 1 to 4,
A method of determining deterioration of a heating wire in a semiconductor manufacturing apparatus, wherein the deterioration of the heating wire is determined when the temperature inside the heater is controlled to a constant temperature. A heat insulating cylinder provided in the heater;
A heating wire disposed in a spiral shape along the inner surface of the heat insulating cylinder;
An inner tube provided inside the heating wire and capable of isolating a substrate to be processed disposed inside from outside air;
A current sensor for measuring a current supplied to the heating wire to determine deterioration of the heating wire;
When the temperature inside the heater is controlled to a predetermined temperature by the heat of the heating wire supplied with current, a calculated value calculated based on the current value of the current supplied to the heating wire is obtained in advance. A deterioration determination means for determining that the heating wire is deteriorated based on a comparison between the calculated value and the deterioration value, in comparison with a deterioration value as a value indicating deterioration of the heating wire;
A semiconductor manufacturing apparatus comprising:

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