A temperature control device for preventing product from being deposited due to condensation and a control method thereof

Abstract

The present invention discloses a temperature control device and a control method thereof for preventing the deposition of products due to condensation. The temperature control device includes a factory water inlet pressure regulating valve, a water inlet manual valve, a solenoid valve, a first water flow meter, a contact thermometer, a proportional solenoid valve, a second water flow meter, a control module, a water return manual valve, a temperature setting module and an alarm collection module; in a non-production state, the water inlet manual valve, the solenoid valve and the water return manual valve are controlled to be opened, and the proportional solenoid valve is closed; in a production state, the water inlet manual valve and the water return manual valve are controlled to be opened, the solenoid valve is closed, and the proportional solenoid valve is controlled to be opened or closed. This technical solution makes the temperature of the front furnace door in production higher than the temperature of the product condensation deposition in the production of the low-pressure chemical vapor deposition equipment, thereby greatly reducing the amount of product condensation deposition in the front furnace door. In this way, the risk of contamination of the produced wafers can be reduced, and the frequency of cleaning the front furnace door can be greatly reduced, and the risk of furnace tube rupture caused by repeated heating and cooling of the front furnace door during cleaning can be reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor equipment, and specifically relates to a temperature control device for preventing products from being deposited on a front furnace door due to condensation during the production of low-pressure chemical vapor deposition equipment, and a control method for the temperature control device. Background Art

[0002] In semiconductor equipment, in the production of low-pressure chemical vapor deposition equipment, the furnace temperature can normally reach 600 to 800 degrees Celsius, and circulating water is required to cool the front furnace door. The equipment is generally cooled by circulating water at 0.3Mpa.

[0003] Under the above conditions, the temperature of the front furnace door during production is generally not higher than 80 degrees Celsius. For silicon nitride, silicon oxide, silicon carbide, etc., there will generally be product condensation and deposition at the front furnace door after production. After the equipment is used for a long time, the product at the front furnace door will form a thick layer along the front furnace door, which will contaminate the produced wafers.

[0004] Therefore, in this temperature control mode, the furnace tube needs to be cooled down regularly to clean the front furnace door. The quartz furnace tube is repeatedly heated and cooled, which is relatively easy to cause cracks due to stress differences and other reasons. After cleaning, equipment verification and process verification are also required, which is also time-consuming.

[0005] In summary, conventional water cooling of the front furnace door of low-pressure chemical vapor deposition equipment will cause the products to condense and deposit on the front furnace door during equipment production, which will contaminate the produced wafers. At the same time, the equipment also needs to be cooled down regularly to open the cavity and clean the front furnace door. Therefore, a temperature control device is needed to prevent the products from condensing and depositing on the front furnace door during the production of low-pressure chemical vapor deposition equipment, and this case is generated. Summary of the invention

[0006] The purpose of the present invention is to provide a temperature control device and a control method for preventing the product from being deposited due to condensation, so that the temperature of the front furnace door in production is higher than the temperature of the product condensation and deposition in the production of low-pressure chemical vapor deposition equipment, thereby greatly reducing the amount of product condensation and deposition on the front furnace door. In this way, the risk of contamination of the produced wafers can be reduced, and the frequency of cleaning the front furnace door can be greatly reduced, thereby reducing the risk of furnace tube rupture due to repeated heating and cooling of the front furnace door when cleaning.

[0007] In order to achieve the above object, the solution of the present invention is:

[0008] A temperature control device for preventing a product from being deposited due to condensation, comprising a plant service water inlet pressure regulating valve, a water inlet manual valve, a solenoid valve, a first water flow meter, a contact thermometer, a proportional solenoid valve, a second water flow meter, a control module, a water return manual valve, a temperature setting module and an alarm collection module, wherein one end of the plant service water inlet pressure regulating valve is connected to a plant service water supply line, and the other end is connected to one end of the water inlet manual valve, and the other end of the water inlet manual valve is divided into two branches, one branch is connected to the input port of a front furnace door water cooling system through a solenoid valve and a first water flow meter, and the other branch is connected to the input port of the front furnace door water cooling system through a proportional solenoid valve and a second water flow meter; a contact thermometer is pre-buried in the front furnace door water cooling system, and the output port of the front furnace door water cooling system is connected to the plant service water return line via a water return manual valve;

[0009] The control module is electrically connected to the water flow meter, the contact thermometer, and the water flow meter respectively; the temperature setting module is used to set the water temperature of the front furnace door, for the control module to compare the temperature data measured by the contact thermometer, and generate a control signal for the proportional solenoid valve; the alarm collection module is used to collect the water flow alarm signals of the first and second water flow meters under the control of the control module, and send an alarm signal to the machine when the water flow is low.

[0010] It also includes the first to fourth manual valves and N2 purge equipment, wherein the two ends of the N2 purge equipment are respectively connected to the two ends of the front furnace door cooling water channel through the third manual valve and the fourth manual valve, and the first manual valve and the second manual valve are respectively arranged at the two ends of the front furnace door cooling water channel on the water cooling branch.

[0011] As described above, the control method of the temperature control device for preventing the product from being deposited due to condensation controls the status of each component according to whether it is in the production state or not as follows:

[0012] In the non-production state, the water inlet manual valve, solenoid valve and return water manual valve are controlled to be open, and the proportional solenoid valve is closed. Water starts from the plant water supply line, flows along the plant water inlet pressure regulating valve, water inlet manual valve, solenoid valve, water flow meter, front furnace door water cooling system, return water manual valve, and flows to the plant return water line;

[0013] Under production status, the water inlet manual valve and water return manual valve are controlled to be opened, the solenoid valve is closed, and the proportional solenoid valve is controlled to be opened or closed. Water starts from the plant water supply line, passes through the plant water inlet pressure regulating valve, water inlet manual valve, proportional solenoid valve, water flow meter, front furnace door water cooling system, and water return manual valve, and flows to the plant water return line.

[0014] In the above non-production state, when the electrical signal collected by the first water flow meter is zero or close to zero, an alarm signal is fed back to the machine, causing the machine to report an error and cool down.

[0015] Under the above production conditions, the actual temperature of the front furnace door measured by the contact thermometer is compared with the set temperature. When the actual temperature is lower than the set temperature, the opening of the proportional solenoid valve is reduced to reduce the water flow through the front furnace door water cooling system; when the actual temperature is higher than the set temperature, the opening of the proportional solenoid valve is increased.

[0016] In the above production state, when the electrical signal collected by the second water flow meter is zero for a long time, an alarm signal is fed back to the machine, so that the machine controls the front furnace door to switch to the water cooling mode in the non-production state to continue production.

[0017] After adopting the above scheme, when the machine is in production, the circulating water circuit is switched to the water cooling branch with a proportional solenoid valve through the control system. The actual temperature of the front furnace door measured by the proportional solenoid valve and the pre-buried contact thermometer, as well as the set temperature input into the control module, form a closed-loop control system for temperature control, so that the temperature of the front furnace door during production is higher than the temperature of the condensation and deposition of these products, greatly reducing the amount of condensation and deposition of the products on the front furnace door. Under non-production conditions, only one circulating water cooling branch needs to be drawn from the factory circulating water to perform conventional water cooling on the front furnace door. At the same time, by collecting the water flow electrical signal and setting the water flow alarm parameters in the control module, in the event of an emergency, the machine will report an error to cool down or switch to the water cooling method under non-production conditions, so that the front furnace door components will not be damaged due to sudden water outages in the factory, blockage of the internal water circuit of the front furnace door, or aging or damage of the contact thermometer due to long-term use.

[0018] Compared with the prior art, the beneficial effects of the present invention are: at a relatively low cost, the temperature of the front furnace door in production can be higher than the temperature of condensation and deposition of these products, thereby preventing the products in the process production from condensing and depositing on the front furnace door; avoiding the problem of contamination of wafers in production; reducing the number of times the equipment cavity is opened and cleaned due to condensation and deposition of products, saving valuable production time, and also saving equipment verification and process verification time; by collecting water flow electrical signals and setting water flow alarm parameters in the control module, in the event of an emergency, the machine will report an error and cool down or switch to water cooling mode in a non-production state, so that the front furnace door will not be damaged due to sudden water outages in the factory, blockage of the internal water channel of the front furnace door, or aging or damage of the contact thermometer after long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention;

[0020] Figure 2 It is a schematic diagram of the water-cooling temperature control device for the front furnace door in a non-production state of the present invention;

[0021] Figure 3 It is a schematic diagram of the water-cooling temperature control device for the front furnace door in the production state of the present invention;

[0022] Figure 4 It is a schematic diagram of a preferred embodiment of the present invention.

[0023] Reference numerals:

[0024] 1-Factory water inlet pressure regulating valve, 2-Water inlet pressure gauge, 3-Water inlet manual valve, 4-Solenoid valve, 5-Water flow meter, 6-Front furnace door cooling water circuit, 7-Contact thermometer, 8-Proportional solenoid valve, 9-Water flow meter, 10-Control module, 11-Return water manual valve, 12-Return water pressure gauge, 13-Factory water supply line, 14-Factory return water line, 15-Temperature setting module, 16-Alarm collection module, 17-Manual valve, 18-Manual valve, 19-Manual valve, 20-Manual valve. DETAILED DESCRIPTION

[0025] The technical solutions and beneficial effects of the present invention will be described in detail below with reference to the accompanying drawings.

[0026] like Figure 1 As shown, the present invention provides a temperature control device for preventing the product from being deposited due to condensation, comprising a plant water inlet pressure regulating valve 1, a water inlet pressure gauge 2, a water inlet manual valve 3, a solenoid valve 4, a water flow meter 5, a contact thermometer 7, a proportional solenoid valve 8, a water flow meter 9, a control module 10, a return water manual valve 11, a return water pressure gauge 12, a temperature setting module 15 and an alarm collection module 16, wherein the plant water inlet pressure regulating valve 1 is connected to a plant water supply line 13, the plant water inlet pressure regulating valve 1 is connected to one end of the water inlet manual valve 3, and the other end of the water inlet manual valve 3 is divided into two branches, one branch is connected to the input port of the front furnace door water cooling system 6 through the solenoid valve 4, and the branch is also connected to the water flow meter 5, and the other branch is connected to the input port of the front furnace door water cooling system 6 through the proportional solenoid valve 8, and the branch is also connected to the water flow meter 9; the front furnace door cooling water path 6 is pre-buried with a contact thermometer 7, and the output port of the front furnace door cooling water path 6 is connected to the front furnace door cooling water path 6 via the return water manual valve 1 1 is connected to the factory service return water line 14; a water inlet pressure gauge 2 is provided on the line between the factory service water inlet pressure regulating valve 1 and the water inlet manual valve 3, and a return water pressure gauge 12 is provided on the line from the return water manual valve 11 to the factory service return water line 14; in addition, a control module 10 is provided, and the control module 10 is electrically connected to the water flow meter 5, the contact thermometer 7, and the water flow meter 9 respectively, and controls the working states of the solenoid valve 4 and the proportional solenoid valve 8 respectively according to the measured data; the control module 10 includes a temperature setting module 15 and an alarm collection module 16, wherein the temperature setting module 15 is used to set the water temperature of the front furnace door, and is used for the control module 10 to compare the temperature data measured by the contact thermometer 7, and generate a control signal for the proportional solenoid valve 8; the alarm collection module 16 is used to collect the water flow alarm signals of the water flow meter 5 and the water flow meter 9 under the control of the control module 10, and send an alarm signal to the machine when the water flow is low.

[0027] The present invention also provides a control method for the aforementioned temperature control device for preventing the product from being deposited due to condensation, by controlling and adjusting the switching states of the water inlet manual valve 3, the solenoid valve 4, the proportional solenoid valve 8, and the water return manual valve 11, a water cooling working mode in a production or non-production state is realized.

[0028] In the non-production state, the water inlet hand valve 3, solenoid valve 4, and return water hand valve 11 are opened, and the proportional solenoid valve 8 is closed. Figure 2 , a water channel is led from the factory water supply line Supply 13 along the factory water inlet pressure regulating valve 1, the water inlet pressure gauge 2, the water inlet manual valve 3, the solenoid valve 4, the water flow meter 5, the front furnace door cooling water channel 6, the return water manual valve 11, the return water pressure gauge 12, and finally flows to the factory return water line Return 14; at the same time, through the electrical signal collected by the water flow meter 5 and the water flow alarm parameter set in the control module 10, during the non-production process, when the electrical signal collected by the water flow meter 5 is zero or close to zero (the threshold value can be set), the control module 10 will feedback to the machine through the alarm collection module 16, so that the machine will report an error and cool down, so that the front furnace door will not be damaged due to the sudden water outage of the factory.

[0029] In the production state, the water inlet hand valve 3 and the water return hand valve 11 are opened, the solenoid valve 4 is closed, and the proportional solenoid valve 8 is controlled to open or close. Figure 3 As shown, water is led from the plant water supply line 13 along the plant water inlet pressure regulating valve 1, the water inlet pressure gauge 2, the water inlet manual valve 3, the proportional solenoid valve 8, the water flow meter 9, the front furnace door cooling water line 6, the return water manual valve 11, the return water pressure gauge 12, and finally flows to the plant return water line 14; wherein, the proportional solenoid valve is a control valve for controlling the liquid flow, and can perform stepless and smooth adjustment of the input liquid flow by controlling the input current or voltage signal. Figure 3In the embodiment, the actual temperature of the front furnace door measured by the proportional solenoid valve 8 and the pre-buried contact thermometer 7, and the set temperature input into the control module form a closed-loop control system for temperature control. Through this closed-loop temperature control system, when the measured water temperature is lower than the set temperature given to the control module, the proportional solenoid valve is opened less or even temporarily not opened, reducing the water flow through the front furnace door, so that the temperature at the front furnace door can be quickly heated up. When the measured water temperature is close to the set temperature, the opening of the proportional solenoid valve is appropriately increased; when the measured water temperature exceeds the set temperature, for example, exceeds 5 degrees Celsius, the water supply of the proportional solenoid valve is further increased, and the measured water temperature decreases accordingly; when the measured water temperature is lower than the set temperature, for example, 5 degrees Celsius, the water supply of the proportional solenoid valve is reduced. In the entire production state, the water temperature of the front furnace door is controlled at plus or minus 5 degrees Celsius of the set temperature, so that it can be ensured that there is almost no product deposition at the front furnace door due to condensation in the entire production state. At the same time, through the electrical signal collected by the water flow meter 9 and the water flow alarm parameters set in the control module, during the production process, when the collected electrical signal of the water flow meter 9 is zero for a long time, the control module sends an alarm signal to the machine through the alarm collection module 16, and the water cooling of the front furnace door is switched to the conventional water cooling mode, that is, the water cooling mode under the non-production state. After the production is completed, the water cooling branch under the production state is checked for abnormalities and repaired, so that the front furnace door will not be damaged due to blockage of the internal water channel of the front furnace door or aging or damage of the contact thermometer due to long-term use, while ensuring the normal progress of production.

[0030] In the non-production state, the front furnace door is cooled by conventional water cooling. At this time, the water temperature at the front furnace door is lower than 80°C. In the production state, the water cooling system switches the working mode. In order to prevent the deposition of products, the temperature is usually set at around 120°C. When the actual water temperature is lower than the set temperature, the proportional solenoid valve can be opened less or even temporarily closed. Then, when the proportional solenoid valve is closed, the front furnace door heats up quickly. The time required for the furnace tube to heat up from 80°C to 120°C varies depending on the process. The time can be set from 30 minutes to 1 hour. For example, the silicon nitride process of more than 800 degrees can be set to 1 hour, and the silicon oxide process of more than 600 degrees can be set to 45 minutes. If the proportional solenoid valve is closed for a long time without water in the production state, there may be a malfunction of the temperature measuring component or the water circuit. At the same time, the long-term lack of water cooling will cause the sealing ring at the front furnace door to fail.

[0031] When the machine is in a non-production state, there is no need to worry about product deposition. You only need to draw a circulating water cooling branch from the factory circulating water to perform conventional water cooling on the front furnace door. At the same time, collect the signal of the water flow meter of this branch. When the collected water flow is zero or close to zero, the machine will report an error and cool down, so that the front furnace door will not be damaged due to sudden water outage in the factory.

[0032] When the machine is in production, the circulating water circuit is switched to the water-cooling branch connected to the proportional solenoid valve through the control system. The actual temperature of the front furnace door measured by the proportional solenoid valve and the pre-buried contact thermometer, as well as the set temperature input into the control module, form a closed-loop control system for temperature control, so that the temperature of the front furnace door during production is higher than the temperature of the condensation and deposition of these products, greatly reducing the amount of condensation and deposition of the products on the front furnace door. During the production process, when the collected water flow electrical signal is zero for a long time, the control module sends an alarm message to the machine, and the water cooling of the front furnace door is switched to the conventional water cooling mode, that is, the water cooling mode under non-production status ( Figure 2 ), after the production is completed, check the abnormalities of the water cooling branch under production status and repair them, so that the front furnace door will not be damaged due to blockage of the internal water channel of the front furnace door or aging or damage of the contact thermometer after long-term use.

[0033] As a preferred embodiment of the present invention, a N2 (nitrogen) purge device is also provided for the cooling water channel of the front furnace door, and four hand valves 17-20 are provided to cooperate with Figure 4 As shown, the two ends of the N2 purge equipment are connected to the two ends of the front furnace door cooling water channel 6 through manual valves 19 and 20 respectively, and the manual valves 17 and 18 are respectively arranged at the two ends of the front furnace door cooling water channel 6 on the water cooling branch. Specifically, the hand valve 17 is arranged at the input port of the front furnace door cooling water channel 6, and the hand valve 18 is arranged at the output port of the front furnace door cooling water channel 6.

[0034] During operation, when it is necessary to clean the front furnace door cooling water channel 6, first close the hand valves 17 and 18, then open the hand valve 20 first, then open the hand valve 19, and use the 40-60PSI N2 purge equipment to purge the front furnace door cooling water channel 6; after purge for a few minutes, first close the hand valve 19, then close the hand valve 20, and then open the hand valves 18 and 17 in turn. At this time, the impurities purged will be taken away with the help of the water flow in the water-cooling branch; if the front furnace door cooling water channel 6 is relatively dirty, the above operation can be repeated several times to ensure that the cooling water channel is fully cleaned.

[0035] The above embodiments are only for illustrating the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention.

Claims

1. A temperature control device for preventing a product from being deposited due to condensation, characterized in that: It includes a plant water inlet pressure regulating valve, a water inlet manual valve, a solenoid valve, a first water flow meter, a contact thermometer, a proportional solenoid valve, a second water flow meter, a control module, a return water manual valve, a temperature setting module and an alarm collection module, wherein one end of the plant water inlet pressure regulating valve is connected to the plant water supply line, and the other end is connected to one end of the water inlet manual valve, and the other end of the water inlet manual valve is divided into two branches, one branch is connected to the input port of the front furnace door water cooling system through the solenoid valve and the first water flow meter, and the other branch is connected to the input port of the front furnace door water cooling system through the proportional solenoid valve and the second water flow meter; the front furnace door water cooling system is pre-buried with a contact thermometer, and the output port of the front furnace door water cooling system is connected to the plant water return line via the return water manual valve; The control module is electrically connected to the water flow meter, the contact thermometer, and the water flow meter respectively; the temperature setting module is used to set the water temperature of the front furnace door, for the control module to compare the temperature data measured by the contact thermometer, and generate a control signal for the proportional solenoid valve; the alarm collection module is used to collect the water flow alarm signals of the first and second water flow meters under the control of the control module, and send an alarm signal to the machine when the water flow is low; By controlling and adjusting the switch status of the water inlet hand valve, solenoid valve, proportional solenoid valve, and water return hand valve, the water cooling working mode in production or non-production state is realized: In the non-production state, the water inlet manual valve, solenoid valve, and water return manual valve are opened, and the proportional solenoid valve is closed. Water is led from the plant water supply line along the plant water inlet pressure regulating valve, water inlet manual valve, solenoid valve, first water flow meter, front furnace door water cooling system, and water return manual valve, and finally flows to the plant water return line; Under production status, the water inlet manual valve and the water return manual valve are opened, the solenoid valve is closed, and the proportional solenoid valve is controlled to open or close. A path of water is drawn from the plant water supply line along the plant water inlet pressure regulating valve, the water inlet manual valve, the proportional solenoid valve, the second water flow meter, the front furnace door water cooling system, the water return manual valve, and finally flows to the plant return water line; wherein, the actual temperature of the front furnace door measured by the contact thermometer is compared with the set temperature. When the measured water temperature is lower than the set temperature given to the control module, the proportional solenoid valve is opened less or even temporarily not opened, so as to reduce the water flow through the front furnace door, so that the temperature at the front furnace door can be quickly heated up; when the measured water temperature is close to the set temperature, the opening of the proportional solenoid valve is appropriately increased; when the measured water temperature exceeds the set temperature, the water supply of the proportional solenoid valve is further increased, and the measured water temperature decreases accordingly; when the measured water temperature is lower than the set temperature, the water supply of the proportional solenoid valve is reduced; so that the water temperature of the front furnace door is controlled at about plus or minus 5 degrees Celsius of the set temperature under the entire production status.

2. The temperature control device for preventing the product from being deposited due to condensation as claimed in claim 1, characterized in that: It also includes the first to fourth manual valves and N2 purge equipment, wherein the two ends of the N2 purge equipment are respectively connected to the two ends of the front furnace door cooling water channel through the third manual valve and the fourth manual valve, and the first manual valve and the second manual valve are respectively arranged at the two ends of the front furnace door cooling water channel on the water cooling branch.

3. The method for controlling a temperature control device for preventing a product from being deposited due to condensation as claimed in claim 1, characterized in that: Depending on whether it is in production status, the status of each component is controlled as follows: In the non-production state, the water inlet manual valve, solenoid valve, and water return manual valve are controlled to be open, and the proportional solenoid valve is closed. Water starts from the plant water supply line, flows along the plant water inlet pressure regulating valve, water inlet manual valve, solenoid valve, first water flow meter, front furnace door water cooling system, and water return manual valve, and flows to the plant water return line; Under the production state, the water inlet manual valve and the water return manual valve are controlled to be opened, the solenoid valve is closed, and the proportional solenoid valve is controlled to be opened or closed. Water starts from the plant water supply line, the plant water inlet pressure regulating valve, the water inlet manual valve, the proportional solenoid valve, the second water flow meter, the front furnace door water cooling system, and the water return manual valve, and flows to the plant return water line; wherein, the actual temperature of the front furnace door measured by the contact thermometer is compared with the set temperature. When the measured water temperature is lower than the set temperature given to the control module, the proportional solenoid valve is opened less or even temporarily not opened, reducing the water flow through the front furnace door, so that the temperature at the front furnace door can be quickly heated up; when the measured water temperature is close to the set temperature, the opening of the proportional solenoid valve is appropriately increased; when the measured water temperature exceeds the set temperature, the water supply of the proportional solenoid valve is further increased, and the measured water temperature decreases accordingly; when the measured water temperature is lower than the set temperature, the water supply of the proportional solenoid valve is reduced; so that the water temperature of the front furnace door is controlled at about plus or minus 5 degrees Celsius of the set temperature under the entire production state.

4. The control method according to claim 3, characterized in that: In the non-production state, when the electrical signal collected by the first water flow meter is zero or close to zero, an alarm signal is fed back to the machine, causing the machine to report an error and cool down.

5. The control method according to claim 3, characterized in that: In the production state, when the electrical signal collected by the second water flow meter is zero for a long time, an alarm signal is fed back to the machine, so that the machine controls the front furnace door to switch to the water cooling mode in the non-production state to continue production.

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