TWI673433B - Method and apparatus for adjusting operating parameters of a vacuum pump arrangement - Google Patents

Abstract

The invention discloses a method for adjusting operating parameters of a vacuum pump device, which comprises: determining a characteristic of a gas flowing through the vacuum pump device; and setting the vacuum pump based on the determined characteristic of the first gas. Equipped operating parameters. A controller may be configured to perform the method of adjusting the operating parameters provided by the vacuum pump based on the characteristics of the gas.

Description

Method and device for adjusting operating parameters of a vacuum pump

The present invention relates to a method and / or device for adjusting the operating parameters of a vacuum pump, and more specifically, the present invention relates to an automatic adjustment of the vacuum based on the thermal characteristics of a gas flowing through the vacuum pump. Power and temperature limiting methods and / or devices provided by the pump.

A system used in semiconductor or other industrial processes typically includes, inter alia, a processing tool, a vacuum pump with a boost pump and a backup pump, and a cancellation device. In semiconductor manufacturing applications, the processing tool typically includes a processing chamber in which a semiconductor wafer is processed into a predetermined structure. The vacuum pump is equipped to connect to the processing tool to evacuate the processing chamber to create a vacuum environment in the processing chamber for performing various semiconductor processing technologies. The gas evacuated by the vacuum pump from the processing chamber can be directed to the elimination device, which eliminates or decomposes harmful or toxic components of the gas before it is released to the environment.

Many semiconductor processing technologies are associated with injecting various gases into the processing chamber in different steps. Hydrogen is a common gas used in processes such as organometallic chemical vapor deposition (MOCVD), plasma enhanced chemical vapor deposition (PECVD), and silicon epitaxy. Hydrogen-rich gases often exhibit completely different characteristics from gases containing heavier gaseous components. Gases containing a large proportion of hydrogen tend to have a high thermal conductivity, while gases containing a large proportion of heavy gaseous components tend to have a lower thermal conductivity. When a hydrogen-rich gas is drawn through a vacuum pump, the rotor and The temperature difference between the stators tends to be smaller than that when the gas contains a large proportion of gaseous components. Therefore, there is a lower risk of stagnation compared to a vacuum pump that pumps a heavy gas, a vacuum pump that pumps a hydrogen-rich gas, which is attributed to one between the rotor and the stator caused by thermal expansion Collision.

No matter how well the risk of pump stagnation is controlled, it is usually not necessary to fully drive the vacuum pumps used in semiconductor processes. In addition to hydrogen, other heavier gases are also present in various steps in many semiconductor process cycles. In order to accommodate these heavier gases, the power limit of the vacuum pump is usually set appropriately to avoid pump stagnation caused by a collision between the rotor and the stator. Therefore, vacuum pumps tend to be underutilized.

Furthermore, setting the temperature limit of the vacuum pump based on the thermal characteristics of the heavy gas tends to cause frequent nuclear tripping when the vacuum pump sucks the hydrogen-rich gas. The temperature of a vacuum pump is almost always monitored from the outside of the pump casing, and the critical temperature inside the vacuum pump is derived from the external temperature. It is a general industry practice to set limits appropriately based on the external temperature of the vacuum pump to avoid the internal temperature exceeding a predetermined safety level. Due to the high thermal conductivity of hydrogen, the temperature difference between the outside and inside of the vacuum pump when the vacuum pump is pumping hydrogen-rich gas tends to be smaller than the outside and inside of the vacuum pump when the vacuum pump is pumping heavy gas The temperature difference. Because the internal temperature of a vacuum pump tends to be higher than the external temperature, a limit set based on the thermal characteristics of heavy gases may be too conservative for a hydrogen-rich suction gas. This limit can be easily exceeded when vacuum pumping hydrogen-rich gas, with little risk of pump stagnation. This causes a false trip or a false alarm to be triggered.

Conventionally, the speed of the vacuum pump can be adjusted in response to the state of the processing chamber. An example can be found in U.S. Patent No. 6,739,840, which is directed to a method of controlling the vacuum pump to reduce the power consumption of the vacuum pump based on a signal provided by an upstream processing tool indicating whether the processing chamber is in operation. However, this method does not take into account the chemical and other characteristics of the gas evacuated from the processing chamber to maximize the extraction performance of the vacuum pump. No adjustment of power and / or temperature limits of the vacuum pump based on signals generated by the processing tool is also provided Ability.

Therefore, there is a need for a method and / or apparatus for adjusting operating parameters of a vacuum pump based on the thermal characteristics of the gas currently flowing through the vacuum pump.

The present invention is directed to a method for adjusting an operating parameter of a vacuum pump, which includes: determining a characteristic of a first gas flowing through the vacuum pump; and setting the vacuum based on the determining characteristic of the first gas. Operating parameters provided by pump.

The present invention is also directed to a device that includes: a processing tool having a processing chamber; a vacuum pump equipped for evacuating the processing chamber; and a controller configured to respond to a representation The operating parameters of the vacuum pump are set by flowing the information of the characteristics of a first gas provided by the vacuum pump.

However, the construction and operation method of the present invention and the additional objects and advantages of the present invention will be understood from the following description of specific embodiments when read in conjunction with the accompanying drawings.

10‧‧‧System

12‧‧‧Processing chamber

14a‧‧‧Gas source

14b‧‧‧Gas source

16a‧‧‧Control Valve

16b‧‧‧Control Valve

20‧‧‧Vacuum pump equipment

22‧‧‧Boost Pump

24‧‧‧backup pump

30‧‧‧controller

100‧‧‧flow chart

102‧‧‧step

104‧‧‧step

106‧‧‧ steps

108‧‧‧ steps

110‧‧‧step

112‧‧‧step

202‧‧‧Power Consumption Curve of Pumping Hydrogen Pumping Hydrogen

204‧‧‧Power consumption curve of pumping air

Power consumption curve of 206‧‧‧backup pumping air

Power consumption curve of 208‧‧‧ backup pump for pumping hydrogen

210‧‧‧ first predetermined threshold

212‧‧‧Second predetermined threshold

214‧‧‧ third predetermined threshold

220‧‧‧area where pressure is lower than P2

222‧‧‧area where pressure is higher than P3

FIG. 1 is a schematic diagram of a system according to some embodiments of the present invention, in which a processing chamber, a boosting pump, and a backup pump are connected in series.

FIG. 2 is a flowchart illustrating a method for automatically adjusting an operating parameter of a boost pump and a backup pump according to some embodiments of the present invention.

FIG. 3 is a graph comparing power consumption curves of a vacuum pump according to some embodiments of the present invention under various conditions.

The present invention is directed to a method and / or device for adjusting operating parameters of a vacuum pump equipment in response to each of the following: a signal indicating the thermal characteristics of a gas evacuated from a processing tool upstream of the vacuum pump equipment; or A judgment based on the thermal characteristics of the gas provided by the vacuum pump in the power consumption mode flow through the vacuum pump. The vacuum pump equipment may be adjusted in response to the signal received by the vacuum pump equipment from the processing tool. Operating parameter, the signal indicates the chemical and thermal characteristics of the gas evacuated from the processing tool. Without this signal, the thermal characteristics of the gas can be determined by analyzing the power consumption mode. This is because different gases produce different power consumption modes when they flow through the vacuum pump equipment.

FIG. 1 is a schematic diagram of a system 10 according to some embodiments of the present invention, in which a processing chamber 12 and a vacuum pump equipment 20 are connected in series. The vacuum pump is equipped 20 to extract gas from the processing chamber 12 and create a vacuum environment within the processing chamber 12 to perform certain processes such as deposition, etching, ion implantation, epitaxy, and the like. The gases may be introduced into the processing chamber 12 from one or more gas sources, such as those calibrated from 14a and 14b in this figure. The gas sources 14a and 14b may be connected to the processing chamber 12 via control valves 16a and 16b, respectively. The timing of introducing various gases into the processing chamber can be controlled by selectively opening or closing the control valves 16a and 16b. The flow rate of the gas introduced into the processing chamber 12 from the gas sources 14a and 14b can be controlled by adjusting the fluid conduction of the control valves 16a and 16b. As discussed above, many semiconductor processing technologies, such as MOCVD, PECVD, and silicon epitaxy, typically inject hydrogen-rich gas into the processing chamber 12 in one step, and inject other heavier gases in other steps. It should be understood that “hydrogen-rich” means that the molar fraction of the hydrogen component in the gas is 50% or more or its mass fraction is 7% or more.

The vacuum pump equipment 20 includes a boost pump 22 and a backup pump 24 connected in series. The inlet of the booster pump 22 is connected to the outlet of the processing chamber 12. The exit of boost pump 22 is connected to the entrance of backup pump 24. The outlet of the backup pump 24 can be connected to a removal device (not shown in the figure), in which the exhaust gas emitted from the backup pump 24 is treated to reduce the possible harmful effects of the exhaust gas on the environment. The sensor (not shown in the figure) can be implemented in the vacuum pump equipment 20 to collect various measurement data of the boost pump 22 and the backup pump 24, such as temperature, power consumption, pump speed, and the like. The sensor may also be implemented to measure the gas pressure at the inlet and / or outlet of the boost pump 22 and / or the backup pump 24. A controller 30 may be implemented in response to indicating the chemical and thermal characteristics of the gas evacuated from the processing chamber 12 One of the signals is to adjust the parameters of the vacuum pump equipped with 20. This signal can be generated by a processing tool incorporated into the processing chamber 12 or a remote host computer that monitors and controls the processing tool via a local area network or the Internet. This signal may indicate a change in one of the processing recipes in the processing chamber 12, and accordingly cause the controller 30 to adjust the parameters of the vacuum pump equipment 20. In addition, one or more sensors (not shown) arranged on the foreline connecting the chamber 12 and the vacuum pump equipment 20 can be used to determine the nature or characteristics of the gas evacuated from the chamber 12.

Alternatively, the controller 30 may be implemented in the form of a control circuit in the vacuum pump equipment 20, the control circuit may analyze the data to obtain the power consumption modes of the vacuum pump equipment 20 and set the vacuum according to the power consumption modes The pump is equipped with 20 operating parameters.

FIG. 2 shows a flowchart 100 showing one method of automatically adjusting the operating parameters of the vacuum pump equipment 20 according to some embodiments of the present invention. FIG. 3 shows an exemplary graph comparing the power consumption curves of the boost pump 22 and the backup pump 24 under various conditions. Referring to FIG. 2 and FIG. 3, initially, in step 102, the boosting pump 22 and the backup pump 24 are set to hydrogen operating parameters to be suitable for pumping a hydrogen-rich gas. Hydrogen operating parameters may have higher electrical or temperature limits than gravity gas operating parameters. As discussed above, the hydrogen-rich gas has a high thermal conductivity, which results in a low temperature difference between the inside and the outside of a vacuum pump and therefore makes the vacuum pump more difficult to drive.

Step 104 determines whether the power consumption of the boost pump is greater than a first predetermined threshold. If the power consumption is below the first predetermined threshold, the program returns to the beginning of step 104. If the power consumption is above the first predetermined threshold, the routine proceeds to step 106. Step 106 determines whether the power consumption of the backup pump is lower than a second predetermined threshold. If the power consumption is above the second predetermined threshold, the program returns to the beginning of step 104. If the power consumption is lower than the second predetermined threshold, the program proceeds to step 108 where the boost and backup pumps are set to heavy gas operating parameters.

As shown in FIG. 3, the power consumption curve of the boost pump pumping hydrogen is calibrated by 202, and the power consumption curve of the boost pump pumping air is calibrated by 204. Calibration support by 208 The power consumption curve of the pumped hydrogen pump, and the power consumption curve of the pumped air pumped by the back pump is calibrated by 206. Here, hydrogen and air are used as the representative of the hydrogen-rich gas and the heavy gas, respectively, to explain the procedure shown in FIG. 2. The x-axis represents the gas pressure at the inlet of a vacuum pump constructed by a series connected booster pump and a backup pump. The y-axis represents the power consumption of the boost and backup pumps. The horizontal lines calibrated by 210 and 212 represent the first predetermined threshold and the second predetermined threshold, respectively. At the pressure P1, if hydrogen is pumped through the boost pump and the backup pump, the power consumption of the boost pump will drop below the first predetermined threshold value 210, and the hydrogen operating parameters will remain unchanged. However, if the air is pumped through the boost pump and the backup pump, at the pressure P1, the power consumption of the boost pump will be higher than the first predetermined threshold value 210, and the power consumption of the backup pump will be low. At a second predetermined threshold value 212. Therefore, the boost and backup pumps will be set to heavy gas operating parameters.

After the boost pump and the backup pump are set to the heavy gas operating parameters (step 108), the program proceeds to step 110, where the power consumption of the boost pump is compared with a third predetermined threshold value. If the power consumption of the boost pump is higher than the third predetermined threshold, the program returns to the beginning of step 110. If the power consumption of the boost pump is lower than the third predetermined threshold, the program proceeds to step 112, where the rate of the boost pump is compared with a predetermined rate threshold. If the rate of the boost pump is slower than the predetermined rate threshold, the program returns to the beginning of step 110. If the rate of the boost pump exceeds the predetermined rate threshold, the program returns to step 102. In step 102, the boost pump and the backup pump are reset to the hydrogen operating parameters.

As shown in FIG. 3, the horizontal line calibrated by 214 represents a third predetermined threshold. In the graph where the power consumption of the boost pump is lower than the third predetermined threshold, there are two regions, namely, a region 220 having a pressure lower than P2 and a region 222 having a pressure higher than P3. If the boost pump is located in the region 220, its rate will exceed a predetermined rate threshold, and therefore it will be safe to reset the boost and backup pumps back to the hydrogen operating parameters. However, if the boost pump is located in region 222, its rate will be slower than a predetermined rate threshold, which is due to the High pressure at Urano's entrance. In this situation, it is not safe to reset the pumps to the hydrogen operating parameters, because these parameters will drive the pumps too strongly, so there is a risk of exceeding their safety limits.

The disclosed method can adjust the parameters of the vacuum pump equipment based on the data collected from the vacuum pump equipment. If it is determined that a hydrogen-rich gas is sucked through the vacuum pump equipment, the hydrogen operating parameter will be used, which can drive the vacuum pump equipment more strongly than when using heavy gas operating parameters. This enables the vacuum pump equipment to operate at a larger capacity without the risk of the vacuum pump equipment exceeding its power or temperature limits.

Alternatively, the operating parameters of the vacuum pump equipment may be adjusted in response to a signal indicating one of the chemical and thermal characteristics of the gas evacuated from the processing chamber to the vacuum pump equipment. As shown in FIG. 1, the controller 30 may be configured to adjust operating parameters in response to this signal. The controller 30 may be implemented as a stand-alone device or as an integrated part of the vacuum pump equipment 20. In some embodiments of the invention, the signal may be generated by a processing tool incorporated into the processing chamber 12. In some other embodiments of the present invention, the signal may be generated by a host computer that monitors and controls the processing tool and the vacuum pump remotely via a local area network or the Internet. In addition, the signal may be generated by one or more sensors in the preceding line arranged between the chamber and the vacuum pump equipment.

In some semiconductor processes, a vacuum pump is equipped to pump both hydrogen-rich and heavy gases in various steps. Conventionally, if the vacuum pump equipment is designed according to the hydrogen flow, a larger size of the vacuum pump equipment will be needed to avoid pump stagnation when the vacuum pump equipment is pumping heavy gas. Unlike conventional designs, the disclosed methods and devices enable the vacuum pump equipment to adjust or automatically adjust its power or temperature limits in response to the thermal characteristics of the gas flowing through the equipment. Therefore, the method and device can make the vacuum pump smaller in size, and will not lose its suction ability when the vacuum pump is equipped with a hydrogen-rich gas, or it will not be pumped with the vacuum pump. There is a risk of stagnation when sucking heavy gases.

In addition to using the relationship between power consumption and inlet gas pressure to determine the flow through a In addition to the thermal characteristics of the gas provided in the vacuum pump, other relationships can be used to make the determination. For example, the relationship between power consumption and pumping rate can be used to determine the thermal characteristics of the gas flowing through the vacuum pump. As another example, the relationship between power consumption and the temperature of the pump can be used to determine the thermal characteristics of the gas flowing through the vacuum pump. It should be understood that setting the operating parameters of the vacuum pump based on the relationships can be achieved by applying the procedure shown in FIG. 2, and some modifications consider different curve patterns of these relationships. It should be stated that such modifications fall within the scope of the invention.

Although the invention has been illustrated and described herein (as embodied by one or more specific examples), it is not intended to limit the invention to the details shown in the drawings, as this can be done without departing from the spirit of the invention Various modifications and structural changes are made herein within the scope and scope of equivalents to the scope of patent applications. Accordingly, the scope of the accompanying patent application should be stated broadly and in a manner consistent with the scope of the invention, as set forth in the following patent application scope.

Claims (29)

A method for adjusting operating parameters of a vacuum pump device, comprising: determining a thermal characteristic of a first gas flowing through the vacuum pump device; and setting the vacuum pump based on the determined thermal characteristic of the first gas. Operating parameters provided by the pump; wherein the operating parameters include at least one of a temperature and a power limit. The method of claim 1, wherein determining the thermal characteristics of the first gas includes: the vacuum pump is equipped with a step of receiving a signal indicating one of the thermal characteristics. The method of claim 2, wherein the signal is provided by a processing tool provided upstream of the vacuum pump. The method of claim 2, wherein the signal is generated by a sensor in a front line of the vacuum pump equipped with a processing tool connected downstream thereof. The method of claim 4, wherein the sensor is used to directly or indirectly measure the thermal conductivity of the first gas. The method of claim 1, wherein the determining the thermal characteristics of the first gas includes: monitoring a property of the vacuum pump equipment while the vacuum pump equipment is pumping through the first gas; and based on the monitoring Properties to determine the thermal characteristics of the first gas. The method of claim 6, wherein the property is a power consumption mode. The method of claim 1, wherein the vacuum pump is equipped with a booster pump and a backup pump, the booster pump and the backup pump so that the booster pump is located downstream of a processing chamber and the One way upstream of the backup pump is connected in series to the processing chamber. The method of claim 8, wherein determining the thermal characteristics of the first gas includes: determining whether the power consumption of the booster pump at a given time is higher than a first predetermined temperature Limit. If the method of claim 8 or 9, wherein determining the thermal characteristics of the first gas includes: if the power consumption of the booster pump at the given time is higher than the first predetermined threshold, determining the backup Whether the pump's power consumption at a given moment is below a predetermined second threshold. The method of claim 10, wherein determining the thermal characteristics of the first gas includes: if the power consumption of the backup pump at the given time is lower than the second predetermined threshold and the boost pump is in the If the power consumption at a given time is higher than the first predetermined threshold, the first gas is calibrated as a heavy gas. The method of claim 10, wherein if the power consumption of the backup pump is lower than the second predetermined threshold and the power consumption of the boost pump is higher than the first predetermined threshold at the given time , The operating parameters are set as heavy gas operating parameters according to the thermal characteristics of the heavy gas. The method of claim 10, wherein determining the thermal characteristics of the first gas includes: if the power consumption of the backup pump at the given time is higher than the second predetermined threshold value and the boost pump is in the If the power consumption at a given time is higher than the first predetermined threshold, the first gas is calibrated as a hydrogen-rich gas. The method of claim 10, wherein if the power consumption of the backup pump is higher than the second predetermined threshold and the power consumption of the boost pump is higher than the first predetermined threshold at the given moment , The operating parameters are set as hydrogen operating parameters according to the thermal characteristics of the hydrogen-rich gas. The method of claim 13, wherein the hydrogen operating parameters have a power limit for the vacuum pump that is higher than the power limit of the heavy gas operating parameters. The method of claim 13, wherein the hydrogen operating parameters have a temperature limit for the vacuum pump that is higher than the power limit of the heavy gas operating parameters. The method of claim 12, wherein the determining the thermal characteristics of the first gas includes: It is determined whether the power consumption of the boost pump is lower than a third predetermined threshold. The method of claim 17, wherein the determining the thermal characteristics of the first gas includes: if the power consumption of the boosting pump is lower than the third predetermined threshold, determining whether the boosting pump exceeds a predetermined Threshold of rate. The method of claim 17, wherein if the boosting pump exceeds the predetermined rate threshold and the power consumption of the boosting pump is lower than the third predetermined threshold, then according to the thermal characteristics of the hydrogen-rich gas These operating parameters are set as hydrogen operating parameters. The method of claim 7, wherein the power consumption mode includes a relationship between power consumption of the vacuum pump equipment and an inlet pressure of the vacuum pump equipment. The method of claim 7, wherein the power consumption mode includes a relationship between a power consumption of the vacuum pump equipment and a suction rate of the vacuum pump equipment. The method of claim 7, wherein the power consumption mode includes a relationship between a power consumption of the vacuum pump equipment and a temperature of the vacuum pump equipment. A device for adjusting operating parameters equipped with a vacuum pump includes: a processing tool having a processing chamber; a vacuum pump equipped for evacuating the processing chamber; and a controller for An operating parameter of the vacuum pump is set in response to information indicating a thermal characteristic of a first gas flowing through the vacuum pump, and the operating parameter includes at least one of a temperature and a power limit. The device of claim 23, wherein the information is in the form of a signal generated by the processing tool. The device of claim 24, wherein the signal is generated by a sensor in a front line of the vacuum pump equipped with the processing tool downstream. The device of claim 25, wherein the sensor is used to directly or indirectly measure the thermal conductivity of the first gas. The device as claimed in item 23, wherein the information presents a monitoring capability of the vacuum pump equipment Qualitative form. The device of claim 27, wherein the monitoring property includes a power consumption mode. The device of claim 28, wherein the vacuum pump is equipped with a booster pump and a backup pump, the booster pump and the backup pump so that the booster pump is located downstream of a processing chamber and the One way upstream of the backup pump is connected in series to the processing chamber.