KR20060094326A - Apparatus for measuring pressure and method of inspecting operation state of the same - Google Patents

Abstract

In the pressure measuring apparatus and its operating state inspection method, the pressure measuring unit measures an internal pressure of the process chamber and outputs an electrical signal corresponding to the measured pressure. The signal measuring unit for measuring the intensity of the electrical signal output from the pressure measuring device is provided between the pressure control device and the pressure measuring unit for adjusting the pressure of the process chamber in conjunction with the electrical signal. The process chamber is maintained at a reference pressure. The pressure measuring device measures the reference pressure of the process chamber. As a result, the operation state of the pressure measuring device can be easily confirmed by comparing the output voltage displayed on the signal measuring unit with the reference voltage corresponding to the measured reference pressure.

Description

Apparatus for measuring pressure and method of inspecting operation state of the same}

1 is a schematic diagram illustrating a pressure measuring apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart for describing a method for checking an operating state of the pressure measuring device illustrated in FIG. 1.

FIG. 3 is a schematic diagram illustrating a vacuum and exhaust system of a vertical chemical vapor deposition apparatus having the pressure measuring apparatus of FIG. 1.

Explanation of symbols on the main parts of the drawings

100: pressure measuring device 110: pressure measuring unit

120: first chamber 130: sensor

140: second chamber 150: signal measuring unit

152: display

The present invention relates to a pressure measuring device. More particularly, the present invention relates to a pressure measuring device for measuring an internal pressure of a process chamber and a method of inspecting an operating state thereof.

In general, a semiconductor device includes a Fab process for forming an electrical circuit on a silicon wafer used as a semiconductor substrate, an electrical die sorting (EDS) process for inspecting electrical characteristics of the semiconductor devices formed in the fab process; Each of the semiconductor devices is manufactured through a package assembly process for encapsulating and individualizing the epoxy resins.

The fab process includes various unit processes, and the unit processes are repeatedly performed to form an electrical device on a semiconductor substrate. The unit processes include a deposition process, a photolithography process, an etching process, a chemical mechanical polishing process, an ion implantation process, a cleaning process, an inspection process, and the like.

In performing the above-mentioned unit processes, more precise control of process conditions such as pressure and temperature has emerged as an essential requirement for improving quality and yield of semiconductor devices.

In the case of a chemical vapor deposition (CVD) process in which a predetermined film is deposited on a semiconductor substrate, various source gases are used depending on the film quality to be deposited. At this time, the process is generally carried out in a predetermined vacuum state in order to prevent the semiconductor substrate from reacting with the atmosphere.

Specifically, when the reaction gases are introduced into the process chamber, the pressure inside the process chamber is temporarily increased. At this time, a pump system is operated to maintain the elevated pressure at a predetermined process condition. In addition, the pump system serves to continuously discharge the unreacted gas and reaction by-products generated in the process of the process.

The method of the pump system varies according to the processing apparatus, and various valves are installed in the exhaust line of the process chamber to control the process conditions. The exhaust system for discharging the process gas largely includes an exhaust line connected with the process chamber, a valve installed on the exhaust line, and a pump connected with the process chamber through the exhaust line.

In addition, a pressure measuring device for measuring the pressure of the process chamber and an auto pressure controller (APC) for controlling the pressure of the process chamber are generally provided on the exhaust line. The pressure measuring device can accurately measure the actual pressure of the process chamber, and a Baratron capacitance manometer (hereinafter referred to as a "baratron gauge") which is not affected by the type of gas being measured. Widely used in industrial sites. The automatic pressure control device adjusts the pressure in the process chamber according to the output voltage of the baratron gauge.

Meanwhile, various process byproducts may be generated as a predetermined substrate processing process is performed in the process chamber. In particular, when particles in the form of powder are generated, the particles may enter the baratron gauge and aggregate to the pressure sensor. Then, the sensor malfunctions and an error occurs in the output voltage. That is, the zero of the baratrone gauge is shifted in the positive or negative direction. Accordingly, periodic zeroing of the baratrone gauge is essential.

However, there remains a problem that the automatic pressure control device is abnormally controlled according to the error of the output voltage from the time when the zero point is shifted to the zeroing operation. Therefore, since the pressure in the process chamber may not be maintained at the preset pressure during the time, the abnormal process may be performed to reduce productivity.

A first object of the present invention for solving the above problems is to provide a method that can easily check the operating state of the pressure measuring device by comparing the reference pressure of the process chamber and the output voltage of the pressure measuring device.

It is a second object of the present invention to provide a pressure measuring apparatus capable of performing a method for inspecting an operating state of a pressure measuring apparatus as described above.

In accordance with an aspect of the present invention, there is provided a method for inspecting an operating state of a pressure measuring apparatus, the method including: maintaining an internal pressure of a process chamber at a reference pressure, and a pressure to test a pressure inside the process chamber; Measuring by using a measuring device, and comparing the output voltage output from the pressure measuring device with a reference voltage corresponding to the reference pressure.

Pressure measuring apparatus according to the present invention for achieving the second object, the pressure measuring unit for measuring the internal pressure of the process chamber and outputs an electrical signal corresponding to the measured pressure, the electrical output from the pressure measuring unit It is provided between the pressure control device for adjusting the pressure of the process chamber in conjunction with the signal and the pressure measuring unit and includes a signal measuring unit for measuring the intensity of the output electrical signal.

According to the present invention as described above, it is possible to easily check the operating state of the pressure measuring device using the output voltage of the pressure measuring device and the reference pressure of the process chamber, pressure measurement by performing a zero adjustment operation according to the comparison result The measurement error of the device can be compensated for. Therefore, the time loss required for periodic performance of the zeroing operation is reduced, the throughput of the substrate processing apparatus is improved, and the productivity of the semiconductor device is improved.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram illustrating a pressure measuring apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the pressure measuring apparatus 100 of the illustrated process chamber 10 includes a pressure measuring unit 110 and a signal measuring unit 150. The pressure measuring unit 110 includes a first chamber 120 for receiving a fluid, a second chamber 140 for forming a vacuum, and a sensor 130 for measuring the pressure of the fluid.

The sensor 130 includes a first electrode 136, a second electrode 132 that is movable with respect to the first electrode 136, and the first electrode 136, and first and second electrodes 136 and 132. Genetic material interposed therebetween.

The first electrode 136 includes a support part 138, a flat internal electrode 136a on the support part 138, and a metal external ceramic including a ring-shaped external electrode 136b surrounding the internal electrode 136a ( metal on ceramic) structure. The second electrode 132 is flat and has a predetermined elasticity. The material of the first and second electrodes 136 and 132 is an alloy having a relatively low expansion rate such as an alloy of nickel and iron.

The fluid is received through the inlet 122 formed at one side of the first chamber 120, and the separation distance of the second electrode 132 from the first electrode 136 is changed by the pressure of the fluid. The inlet 122 is provided with a baffle 124 to prevent the second electrode 132 from being damaged by a high pressure. One side of the second chamber 140 is provided with a pump 144 for forming a pressure of the second chamber 140 to a pressure lower than the measured pressure. In particular, a getter pump is preferable as the pump 144.

The signal measurer 150 measures the intensity of the output voltage generated by the sensor 130 of the pressure measurer 110. Specifically, the signal measuring unit 150 is installed on the signal line 154 connecting the pressure measuring unit 110 and the APC 20 to measure a substantial voltage signal input to the APC 20. In order to display the measured voltage signal, the signal measuring unit 150 is provided with a display 152. The illustrated display 152 is of digital type, but may be of analog type.

On the other hand, on the exhaust line 12 of the process chamber 10 is provided with a vacuum pump 30 for controlling the exhaust and vacuum degree. The exhaust line 12 is provided with the APC 20 and the throttle valve 22, the pressure control device 100 is a branch line 14 branched between the process chamber 10 and the APC 20. It is provided on). The APC 20 maintains a constant pressure in the process chamber 10 by controlling the degree of opening and closing of the throttle valve 22 while exchanging data such as voltage and pressure with the pressure control device 100.

The operation state inspection methods of the same pressure measuring device 100 will be described as follows.

The pressure measuring device 100 described above has a very narrow range of tolerance because the resolution of the pressure measurement is very excellent. In particular, the change in capacitance of the sensor 130 is very sensitive to the separation distance D between the first and second electrodes 136 and 132. However, the second electrode 132 may be affected by various external factors. That is, the positional displacement or gravity of the pressure measuring device 100 may affect the movement of the second electrode 132 so that the separation distance D from the first electrode 136 may change. Alternatively, when the fluid includes a condensable process byproduct (P), the process byproduct (P) may be formed in a powder form and aggregated on the second electrode 132. Accordingly, the elasticity of the second electrode 132 is reduced so that the pressure of the fluid is not measured accurately. This is required to check the operating state of the pressure measuring device 100 because a problem occurs that the zero of the output voltage is shifted.

2 is a method for checking an operating state of a pressure measuring device according to an embodiment of the present invention.

Referring to FIG. 2, first, an internal pressure of the process chamber 10 is maintained at a reference pressure (S100). To set the reference pressure, the opening and closing degree of the throttle valve 22 is manually set, and then the angle of the throttle valve 22 and the pumping amount of the vacuum pump 30 are adjusted to correspond to the reference pressure to be set. .

Subsequently, the internal pressure of the process chamber 10 is measured using the pressure measuring device 100 to be inspected (S110). The signal measuring unit 150 of the pressure measuring device 100 changes and displays the pressure sensed by the pressure measuring unit 110 into an output voltage.

Next, the output voltage output from the pressure measuring device 100 and the reference voltage corresponding to the reference pressure are compared with each other (S120).

Table 1 below is an example of a reference table indicating the output voltage of the pressure measuring device 100 with respect to the measured pressure of the process chamber 10. The unit of pressure is pascal and the unit of voltage is Volt. Here, since the pressure and the voltage have a linear proportional relationship, the reference voltage corresponding to the set reference pressure may be calculated through Table 1 above.

As a result of the comparison, by checking whether the difference between the output voltage and the reference voltage satisfies a preset allowable range, the operating state of the pressure measuring apparatus 100 may be easily determined.

Finally, when the difference between the output voltage and the reference voltage is outside the preset allowable range, the output voltage is adjusted to satisfy the allowable range (S130). The adjustment of the output voltage is completed by performing zero adjustment on the pressure measuring unit 110. As an example of zero adjustment, the output voltage may be set to 0V when the process chamber 10 is at the lowest vacuum degree that can be set.

TABLE 1

pressure Output voltage pressure Output voltage pressure Output voltage pressure Output voltage One 0.08 41 3.08 81 6.08 121 9.08 2 0.15 42 3.15 82 6.15 122 9.15 3 0.23 43 3.23 83 6.23 123 9.23 4 0.30 44 3.30 84 6.30 124 9.30 5 0.38 45 3.38 85 6.38 125 9.38 6 0.45 46 3.45 86 6.45 126 9.45 7 0.53 47 3.53 87 6.53 127 9.53 8 0.60 48 3.60 88 6.60 128 9.60 9 0.68 49 3.68 89 6.68 129 9.68 10 0.75 50 3.75 90 6.75 130 9.75 11 0.83 51 3.83 91 6.83 131 9.83 12 0.90 52 3.90 92 6.90 132 9.90 13 0.98 53 3.98 93 6.98 133 9.98 14 1.05 54 4.05 94 7.05 15 1.13 55 4.13 95 7.13 16 1.20 56 4.20 96 7.20 17 1.28 57 4.28 97 7.28 18 1.35 58 4.35 98 7.35 19 1.43 59 4.43 99 7.43 20 1.50 60 4.50 100 7.50 21 1.58 61 4.58 101 7.58 22 1.65 62 4.65 102 7.65 23 1.73 63 4.73 103 7.73 24 1.80 64 4.80 104 7.80 25 1.88 65 4.88 105 7.88 26 1.95 66 4.95 106 7.95 27 2.03 67 5.03 107 8.03 28 2.10 68 5.10 108 8.10 29 2.18 69 5.18 109 8.18 30 2.25 70 5.25 110 8.25 31 2.33 71 5.33 111 8.33 32 2.40 72 5.40 112 8.40 33 2.48 73 5.48 113 8.48 34 2.55 74 5.55 114 8.55 35 2.63 75 5.63 115 8.63 36 2.70 76 5.70 116 8.70 37 2.78 77 5.78 117 8.78 38 2.85 78 5.85 118 8.85 39 2.93 79 5.93 119 8.93 40 3.00 80 6.00 120 9.00

On the other hand, by repeatedly performing the steps S110 to S130 while changing the reference pressure of the process chamber 10, it is possible to examine the operating state of the pressure measuring device 100 more closely.

As a result, the span and linearity variables between the output voltage and the display pressure of the pressure measuring device 100 may be inspected. When the difference between the span or the proportional value and the preset value is out of the preset allowable range by the inspection, the span or the proportional degree is adjusted to meet the preset value to satisfy the allowable range. At this time, the adjustment of the span and the proportional variable may be made in a span adjustment unit (not shown) and a proportional variable control unit (not shown) provided on one side of the pressure measuring unit 110.

As described above, the method for checking the operation state of the pressure measuring device maintains a reference pressure by manually operating a throttle valve 22 connected to the APC 20, and then the output voltage (measured pressure) of the pressure device and the By comparing the reference pressure. However, the method for checking the operating state of the pressure measuring device may be automatically performed.

Accordingly, the pressure regulation of the process chamber 10 fails due to an error in the output voltage, thereby preventing a process accident on a large amount of substrates. In addition, it is not necessary to periodically perform the zero adjustment operation that takes about 8 hours without inspection can improve the operation rate of the substrate processing apparatus.

Hereinafter, an example of a vacuum and exhaust system having the pressure measuring device of FIG. 1 will be described.

FIG. 3 is a schematic diagram illustrating a vacuum and exhaust system of a vertical chemical vapor deposition apparatus having the pressure measuring apparatus of FIG. 1.

Referring to FIG. 3, the vacuum and exhaust system largely includes an exhaust line 220, a first branch line 222, and a second branch line 224.

Generally, a predetermined processing process for the semiconductor substrate W is performed in the process chamber 210 while maintaining a low pressure. In the case of a chemical vapor deposition process for depositing a predetermined film on the semiconductor substrate W, various reactant gases are used depending on the film quality to be deposited. The selected reactant gases are mixed with each other in the process chamber 210 and used in a process of forming a predetermined film, and then remain in the form of residual gas to be discharged to the outside. The discharged gas is called an exhaust gas.

One end of the exhaust line 220 is connected to the process chamber 210 and the other end thereof is connected to the scrubber 290. The scrubber 290 is a device for treating the exhaust gas, and particularly in the case of a dry scrubber, a scrubber 290 is widely used in a process mainly using a halogen group compound. Exhaust gas of the process chamber 210 is discharged to the outside through the exhaust line 220.

The vacuum pump 280 is installed on the exhaust line 220 connected to the scrubber 290, and provides a vacuum force to the exhaust line 220 to scrub the unreacted gas or reaction by-products in the process chamber 210. 290). The vacuum pump 280 may be largely composed of a booster pump and a dry pump.

The first baratron gauge 230 is provided on the exhaust line 220 adjacent to the process chamber 210 to measure the internal pressure of the process chamber 210. Specifically, the measurement range of the first baratron gauge 230 is 0 to 1000 Torr to check the atmospheric pressure and the presence of vacuum, and to check the slow pumping rate by the vacuum pump 280.

The second baratron gauge 240 is spaced apart from the first baratron gauge 230 on the exhaust line 220. The second baratron gauge 240 also measures the internal pressure of the process chamber 210. Specifically, the second baratron gauge 240 measures the base pressure of the process chamber 210 and checks whether leakage occurs in the process chamber 210. Here, the pressure measurement range of the second baratron gauge 240 is 0 to 1 Torr.

A first air valve 242 is provided between the second baratron gauge 240 and the exhaust line 220 to be opened or closed depending on whether air is supplied. The first air valve 242 prevents the second baratron gauge 240 having a narrower measuring range than the first baratron gauge 230 from being damaged by being exposed to high pressure.

Since the first and second baratron gauges 230 and 240 have the same configuration as those described above with reference to FIG. 1, further detailed description thereof will be omitted.

Meanwhile, as illustrated in FIG. 2, a piranha gauge 250 is provided on the exhaust line 220 adjacent to the process chamber 210. The Pirani gauge 250 measures the degree of vacuum using a Wheatstone bridge. In detail, the pyranee gauge 250 uses the thermal conductivity of the gas under low pressure in proportion to the vacuum degree (pressure of the remaining gas), and checks whether the process chamber 210 is at atmospheric pressure or high pressure.

A second air valve 260 is provided between the second baratron gauge 240 and the vacuum pump 280 to open or shut off the exhaust line 220. The second air valve 260 may form the process chamber 210 in a vacuum state in a short time using the vacuum pump 280.

The APC 270 provided between the second air valve 260 and the vacuum pump 280 is interlocked according to the pressures output by the first and second baratron gauges 230 and 240 to process the chamber 210. ) Pressure is maintained within the preset range.

Meanwhile, the first and second branch lines 222 and 224 branch from the exhaust line 220 between the second baratron gauge 240 and the second air valve 260. The first branch line 222 branches at a location adjacent the second air valve 260 to communicate with the exhaust line 220 between the APC 270 and the vacuum pump 280. The second branch line 224 branches between the branch point of the first branch line 222 and the second baratron gauge 240 to communicate with the exhaust line 220 again between the vacuum pump 280 and the scrubber 290. do. The diameter of the first and second branch lines 222 is preferably smaller than the diameter of the exhaust line 220.

The third air valve 262 is provided on the first branch line 222 and is manually opened and used when the process chamber 210 is gradually vacuumed using the vacuum pump 280. The fourth air valve 264 is provided on the second branch line 224, and when the internal pressure reaches the atmospheric pressure after the predetermined substrate processing process is completed in the process chamber 210, the pirani gauge 250 It is automatically opened by the signal of). Thus, unreacted gas and process by-products in process chamber 210 are exhausted through second branch line 224.

Next, a brief description of the operation of the vacuum and exhaust gas treatment apparatus is as follows.

First, the pressure state of the process chamber 210 is checked by the first Baratron gauge 230 or the Piranha gauge 250. At this time, the first air valve 242 is blocked so that the second baratron gauge 240 is not exposed to high pressure. When the process chamber 210 is at atmospheric pressure, the process chamber 210 is formed in a vacuum state.

Subsequently, the second air valve 260 is blocked to cut off the exhaust line 220, and the second air valve 260 is opened to open the exhaust line 220. 282 or dry pump 282 and booster pump 284 operate simultaneously to pump process chamber 210.

Here, the base pressure of the process chamber 210 is checked by the second baratron gauge 240, and it is checked whether the vacuum leaks. In addition, the normality of the pressure adjusted according to the opening and closing degree of the throttle valve of the APC 270 is also checked.

When the pressure inside the process chamber 210 is in a desired state, the reaction gas flows in from the gas providing unit and the substrate processing process is performed. At this time, the pressure of the process chamber 210 is automatically adjusted by the APC 270. When the substrate processing process is completed, a purge gas is supplied to form a pressure of the process chamber 210 at atmospheric pressure.

Finally, the fourth air valve 264 is opened when the atmospheric pressure of the process chamber 210 is sensed by the Pirani gauge 250. Thus, residual gas comprising reaction by-products generated during the process is discharged through second branch line 224.

According to the present invention as described above, the operation state inspection method of the pressure measuring device is made by comparing the output voltage of the signal measuring unit provided in the pressure measuring device with a reference voltage corresponding to the reference voltage set in the process chamber.

Therefore, the operating state of the pressure measuring device can be easily confirmed, and it is not necessary to periodically perform zero adjustment of the pressure measuring device. Accordingly, it is possible to easily prevent an abnormal process from proceeding in the process chamber.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (5)

Maintaining the internal pressure of the process chamber at a reference pressure; Measuring the pressure inside the process chamber using a pressure measuring device to be inspected; And And comparing the output voltage output from the pressure measuring device with a reference voltage corresponding to the reference pressure with each other. The method of claim 1, further comprising adjusting the output voltage so that the difference satisfies the allowable range when the difference between the output voltage and the reference voltage is outside a preset allowable range. Method of inspection of the operating state of the pressure measuring device. A pressure measuring unit for measuring an internal pressure of the process chamber and outputting an electrical signal corresponding to the measured pressure; And It is provided between the pressure control device for adjusting the pressure of the process chamber in conjunction with the electrical signal output from the pressure measuring unit and the pressure measuring unit, including a signal measuring unit for measuring the intensity of the output electrical signal Pressure measuring device, characterized in that. The pressure measuring device of claim 3, wherein the signal measuring unit is a voltmeter. 4. The pressure measuring device of claim 3, wherein the pressure measuring unit comprises a capacitance manometer.

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