TW440926B - Gas mixing and feeding method and its device - Google Patents

Abstract

To provide a gas mixing and feeding device for diluting high density diborane gas with hydrogen gas, and for feeding it to an epitaxial device. The feeding source of diborane gas and a mixer 5 are connected through a duct having a rough mixing line 2a and a fine adjustment mixing line 2b, and the feeding source of hydrogen gas and the mixer 5 are connected through a duct, having a rough mixing line 10a and a fine adjustment mixing line 10b. High density diborane gas is mixed with hydrogen gas by the mixer 5 and fed via a buffer container 3 to a use point. A gas volume detecting sensor 18 detects the usage of gas, and an arithmetic control part 21 and a control drive signal outputting part 22 control the valve opening of flow rate controllers 12a and 13a at a set mixing rate for generating mixed gas with a volume proper for the usage. A two-output type adjuster 31 controls flow rate control valves 12b and 13b for correcting the deviation of the mixed gas density which is detected by a gas density detecting sensor 15.

Description

r] Q 2 β __ Case No. 891Q1fiia V. Description of the invention (υ Field of invention The present invention relates to mixing at least two kinds of gases into a set mixing ratio, and then supplying it to a desired use point such as an epitaxial device (use Site) Gas mixing supply method and device for a mixed gas with a stable mixing ratio. Known technology In the field of the semiconductor industry, gas is often used to process semiconductors. For example, in the process of silicon epitaxial wafers using epitaxial devices, in order to control epitaxy The resistivity of the film will be widely used as a doping gas with diboron gas (B2 Hs / H2) diluted to about 1000 ppm with hydrogen Η2. Figure 3 is a general system for supplying diborane gas to an epitaxial device. A high-pressure vessel 1 equipped with a diborane gas diluted with hydrogen to about 100 ppm is provided at the gas supply source of the doped gas. The diborane gas diluted in the high-pressure vessel 1 is provided with a valve, a filter, and the like as required. The piping line 2 made of components is supplied to the epitaxial device (not shown in the figure) at the point of use (place of use). In addition, '4 in Fig. 3 is the height of the diborane gas released. The container 1 is a high-pressure container that contains nitrogen for purging the required part of the piping line 2 with nitrogen. The problem to be solved by the invention is generally the manufacture of a silicon wafer with an epitaxial device. During the continuous operation of the device during the month, the use mode of the device is suspended every time the device is passed. In the case of using the system of Figure 3 for the resistivity control of the epitaxial film, the diborane gas of the high-pressure vessel 1 The use of a thin gas with a concentration of 1,000 ppm used at the point of use, consumes more per unit time, and is required during the continuous operation of the device

7054-2918-Pfl-ptc Page 4 440926---" " ........................... V. Invention Description (2) Frequent Replace the high pressure container 1. But “Diborane gas of high-pressure vessel 1 is different in manufacturing batch number” and is it measured in B? There are some changes in the degree of farming. Immediately after the replacement of the high-dust container 1 ', due to the change in the concentration of the appearance gas, Mengsheng hindered the best control of the resistivity. In addition, if the pressure is changed per g, the container 1 may be stained. The possibility of dyeing is also a problem in the quality of semiconductor processing. In addition, "the high-pressure container 1 is frequently replaced, so the cost of the high-pressure container is increased", which causes a problem that the manufacturing cost becomes high. The present invention was conceived in order to solve the above-mentioned problems, and an object thereof is to provide a gas mixing supply method and a device thereof, and to avoid replacing a high-pressure container for supplying a gas such as diborane gas during the continuous operation of each device. It can prevent the bad phenomenon caused by replacing the high-dust container, and can supply a fixed and stable mixed-concentration process gas during the continuous operation of the device. Means for Solving the Problem In order to achieve the above object, the present invention has the following structure as a means for solving the problem. That is, the invention of the gas mixing and supply method, the peripheral gas mixer mixes the first gas supplied from the first gas supply source and the second gas supplied from the second gas supply source, and then supplies the second gas and the second gas at the use point. Gas mixture supply method for gas mixture. A gas supply pipeline from the first and second gas supply sources to the gas mixer is formed by using two pipelines of a coarse mixing pipeline and a fine adjustment mixing pipeline. , The two crude mixing pipelines supply the gas mixer with

Page 5 4 40 92 6 V. Description of the invention (3) The amount of coarse mixed gas used at the point of use, and the concentration of the mixed gas relative to the supply of the two gases are used as the supply source of the gas mixture donor. The gas mixer of the second gas supply supplier, the gas supply pipe of the mixer is formed in the pipeline of the two systems, and the measurement of the gas mixing donor mixing supply device is used at the point of use, and the Use this gas as the set value of the gas production amount. It is made by the 犋 mixing pipeline and its mixing amount becomes the challenge. In addition, the problem is solved. In addition, the mixture is discharged from the gas mixing coupler. The determination of the gas mixing ratio should be adjusted according to the fine adjustment of the deviation and the supply amount of the first gas. The adjustment of the mixing pipe should eliminate the first-gas and second-thickness deviations as a means to solve the problem. The first invention of ^ is provided with a rough mixing pipe that is configured to supply a mixed gas of 1 body and a second gas from a supply source of a first gas-gas and a second gas y ^ m ^ ^ ^ " And fine-tuning the mixing pipeline 3rd and 2nd each teaching board 4 people " separating the rolling body supply source to the gas path 'as a means to solve the problem. The second invention for the device is equipped with the gas first The structure of the invention has a gas amount detection sensor for measuring the amount of gas used in the structure. The gas detected by the detection sensor makes the weekly volume to be distributed according to the set gas mixing ratio. The gas mixing control installation means for controlling the set value of the gas production amount by the supply amount of the gas and the second gas. The third invention of the supply device is provided with a detection device for measuring the mixing concentration of the mixing concentration of the self-gas. After the deviation of the set mixing concentration between the first gas and the second gas, the fine-tuning control device for controlling the gas concentration of the first gas supplied to the gas mixer through the mixing pipeline is taken as a solution

V. Description of the invention (4) Means of the subject. In addition, the fourth invention of the gas mixing supply device uses a mixed concentration detection device as an infrared absorption type gas concentration detection sensor as a means to solve the problem. In addition, the fifth invention of the gas mixed supply device is the structure of the first or second or third or fourth invention provided with the gas mixed supply device, and the first gas system is doped with a high concentration of doped gas and the second gas system. The pure gas used to dilute the doping gas is used as a means to solve the problem. In the present invention, a gas amount detection sensor is used to detect the amount of use of the mixed gas at the point of time. In addition, by using a rough mixing pipe and a gas mixing control device, a gas amount is supplied according to the ratio of the set mixing ratio of the first gas and the second gas, and the amount of the gas is commensurate with the cycle amount. The gas mixer is continuously used at the point of use. The amount of mixed gas is supplied to the point of use. Because the concentration of the mixed gas generated by the rough mixing pipe becomes the set mixing ratio, for example, the first gas and the second gas are controlled according to the flow rate mixing. Due to the fluctuation of the flow rate control, it is assumed that the actual mixing concentration is relative to the set mixing ratio. There is some deviation in the determined setting mixing concentration. However, in the present invention, the concentration of the mixed gas discharged from the gas mixer is detected instantaneously at all times by using the mixing concentration detection device, and the deviation amount from the set mixing concentration is instantaneously calculated according to the detected value, for example, as in the first When the mixed concentration of the gas is low, the supply amount of the first gas is increased only to eliminate the deviation, and when the mixed concentration of the first gas is high, the supply amount of the second gas is increased only to eliminate the deviation. Use the fine-tuning mixing pipeline to fine-tune the supply of the first gas and the second gas, always mixing the self-gas

4 40 92 6 V. Description of the invention (5) After the concentration of the mixed gas discharged from the coupler is stably adjusted to the set mixed concentration, it is supplied to the use point. In particular, in the present invention, since the first gas and the second gas are structurally mixed, a mixed gas that is supplied with a set mixing ratio (set mixed concentration) is generated, and a high-concentration diborane gas and a second gas are used as the first gas. The use of hydrogen 'can reduce the high-concentration diborane gas by diluting a high-concentration (for example, 100 ppm) diborane gas with hydrogen and supplying the diborane gas at a thin concentration (for example, 100 ppm) at a predetermined mixing ratio to the epitaxial device. The consumption per unit time does not need to replace the high-pressure vessel of the high-concentration diborane gas supply during the continuous operation of the device, and can continuously supply the stable dilute diborane gas with a constant concentration in the epitaxial device. Embodiments of the Invention Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a gas mixing and supplying apparatus according to the present invention, and FIG. 2 shows a peranatane gas supplying system including the apparatus of this embodiment. This system. Ij y- .. * \ · is excited by hydrogen #. High concentration of diborane gas: supplied to the epitaxial device. In addition, in the following description, the same reference numerals are assigned to the elements corresponding to the constituent elements shown in FIG. 3 of the conventional example, and repeated descriptions thereof are simplified or omitted. In Figure 2 'A plurality of high-pressure vessels (four in Figure 2) are arranged in the diborane gas supply source. No:' Each high-pressure vessel 9 is filled with hydrogen and diluted to a high concentration of 10,000 ρριη as the first gas. Diborane gas. The delivery channels of each high-pressure vessel 9 are combined into a piping line 2 ′ The piping line and 2 branch into a rough mixing line? a and fine-tune the mixing pipe 2b, then combine them and connect them with the gas mixer (hereinafter simply referred to as the mixer) 5. The branch pipe may be a branched pipe, but

Page 8 440926 Revised

_Case No. 891016U

W7LT V. Description of the invention (6) If the branch pipe of the example in FIG. 2 is explained in more detail, the rough mixing pipe 2a becomes the pipe extending the piping pipe 2 and the fine adjustment mixing pipe 2b becomes the extension pipe. Bypass line. On one side, a piping line 10 equipped with components such as a check chamber 6, a filter 7, and various required valves 8 is led from a source of hydrogen gas as a second gas, and the piping line 10 is branched into a coarse mixture. The pipeline 10 a and the fine-tuning mixing pipeline 1 Ob are combined and connected to the mixer 5 to communicate. The branch pipe may be a branched pipe, but the coarse mixing pipe 10a shown in FIG. 2 is formed by an extension pipe of the piping pipe 10, and the fine-tuning mixing pipe 1 Ob becomes the extension pipe 10. (10a) The bypass line. The rough mixing line 2a and the rough mixing line 1 Oa are configured in the mixer 5 so that the high-concentration diborane gas supplied from the high-pressure vessel 9 through the piping line 2 and the supply source of hydrogen are supplied through the piping line 10 Coarse mixing line of a system for rough mixing of hydrogen, the fine adjustment mixing line 2b and the fine adjustment mixing line 1 Ob constitute a high-concentration diborane gas supplied from the high-pressure container 9 through the piping line 2 in the mixer 5 It is a fine-tuning mixing line of a system that is a system for fine-tuning and mixing hydrogen supplied from a hydrogen supply source through a piping line 10. In addition, a flow control device (mass flow controller) for controlling the flow rate by using the valve opening degree of the mixing ratio of high-concentration · degree diborane gas and oxygen is inserted in the coarse mixing pipes 2 a and 10 a.

1 3a. Flow control valves 12b and 1b are installed in the fine-tuning mixing lines 2b and 1 Ob to make use of the variable control of the valve opening. In addition, the mass flow controller (flow control device) may be used instead of the flow control valve to construct the flow control valve D. At the outlet of the mixer 5, a mixed gas supply line 14 is connected. The mixed gas supply line 14 is sequentially passed through the function. Mixed concentration

7 0 5 4-2918-?? l.pU Page 9 Amendment 4 Q 9 2 June ---- Case No. 89101614 n V. Description of the invention ⑺ ^ Gas concentration detection sensor i 5 for reading device 、 Mixer Buffer 1 6 ^ Sight gas concentration ballast sensor 17 、 Gas volume detection sensor (mass meter) 18 、 Buffer container 3 etc. are guided to random ones not shown in the figure On the evening of operation, the epitaxial device is used. The gas concentration detection sensor 丨 5 is an instantaneous and continuous I-name / the infrared absorption type of the concentration of the mixed gas of diboron and argon discharged from the mixer 5 (the concentration of diborane gas) Line sensor. The pipeline sensor is a sensor that is directly measured in the pipeline after discarding the sampled gas after detecting the concentration of the gas. The mixer buffer 16 is a buffer tank for averaging the air pressure discharged from the mixer 5. Monitoring gas concentration detection sensor π is an infrared absorption type pipeline sensor that monitors the concentration of gas mixtures that are averaged by air pressure. This monitoring | uses the detection signal of the gas concentration detection sensor 17 to the monitoring device (Not shown in the figure), etc., when the monitoring gas concentration detection sensor 17 detects an abnormality in concentration, the monitoring device is used to notify the abnormality ^ The gas amount detection sensor 18 uses flow measurement to detect the The amount of mixed gas used at the point of use of the epitaxial device (the amount used per unit time). In addition, the mixed gas supply line 14 between the gas amount detection sensor 18 and the buffer container 3 is branched to a degassing line 19, and the degassing line 19 is passed through a pressure maintaining valve (back pressure adjustment) Device) 2 0 outside the guidance system. When the pressure rises above the set pressure, the pressure-retaining valve 20 discharges the pressure of the rising amount to the system through the degassing line 19, and maintains the pressure of the buffer container 3 at the set pressure, such as the fixed pressure of the epitaxial device. Mixed gas acts. The first feature of this embodiment is to use the coarse mixing pipelines 2a, 10a to continuously and continuously generate a high concentration in accordance with the set mixing ratio.

7054-2919-PFi · ρϊ p. 440 926

Case No. 89101614 V. Description of the invention (8) The structure of the component used in the epitaxial device and point of the crude mixed gas of diborane gas and hydrogen. In addition, the second feature of this embodiment is to use the finely-adjusted mixing pipes 2 b and 1 0 b to eliminate C to correct the deviation amount to zero.) Using the coarse mixing pipes 2 a and 10 a The structure of the deviation of the indifference (the deviation from the set concentration). § The structure of the first feature is shown in FIG. 1 'It is composed of a gas amount detection sensor 18 and a gas mixing control device. The gas mixing control device has an arithmetic control unit (signal generator) 21 and a control driving signal. The structure of the input section, 22C in Figure 1 is to simplify the illustration, and there is one output in the daytime bus, but there are two outputs on the bus, and X 2 is shown in Figure 1 for two rounds) and the flow device 1 2 a, 1 3 a. The gas amount detection sensor 18 detects the amount (flow rate) of the mixed gas discharged from the mixer buffer 16 and supplies it to the calculation control unit 21 as the gas usage amount in the epitaxial device ^ use point. pv. In the calculation control unit 21, a data storage unit such as a set mixing ratio of high-concentration diborane gas and hydrogen of 1: 9 is supplied in advance. The calculation control unit 2 takes the detected value PV as the gas generation amount setting value SV Temporarily stored in the memory, calculate the difference to obtain the high-concentration diborane gas volume (flow rate) and hydrogen volume (flow volume) required for the mixed gas volume other than the gas generation volume set value according to the set mixing ratio. The 'control drive signal wheel output section 22' then sends the calculated value as a set value signal to the flow control devices 12a, 13a. The flow control devices 12a and 1a use the control valves in the flow control devices 12a and 13a and the built-in PID controller to control the gas flow to the set flow signal according to the set value signal. Send out the gas. That is, if the flow control device 12a becomes the high concentration of the set value signal,

7054-2913-PFl-ptc Page 11 440926 _ __89101614 _ revision five, description of the invention (9) Diborane gas flow rate control valve opening results, through the crude high concentration of ethylene ) Becomes the high-concentration diborane gas amount calculated by the arithmetic control unit 21. Similarly, the flow control device 13a controls the result of the opening degree as if the hydrogen flow rate of the setpoint signal becomes' the hydrogen amount (flow rate) through the rough mixing pipe 10a becomes the hydrogen calculated by the operation control section 21 the amount. As shown above, 'Results of the valve opening amount control of the flow control device (mass flow controller) 1 2 a, 1 3 a according to the detection result of the gas usage amount of the gas amount detection sensor 18' use the rough The mixing pipelines 2 a and 10 a continuously and continuously generate a mixed gas (coarse mixed gas) at a point of use that is a mixture of a high-concentration diborane gas and hydrogen at a set mixing ratio, and then supplies it to the point of use. The second characteristic structure of this embodiment is constituted by a gas concentration sensor 15 and a gas concentration fine adjustment control device. The gas concentration fine adjustment control device has a two-output regulator 31, a flow control valve 12b, and a flow control.阙 1 3b. The structure of the second feature is set to I in order to correct the deviation (deviation from the set mixture concentration) of the mixed gas concentration (diborane gas) generated by using the rough mixing pipe 2 a, i 0 a. That is, using the mixed gas of the rough mixing pipelines 2a and 10a, the gas amount of the gas generating set value SV (generating target gas amount) is distributed into a local concentration of B and alkane gas according to the ratio of the set mixing ratio

Mixing line 2 a

Hybrid equivalent 'Using flow ^ system control 12a, l3a flow control Yansheng = mixed milk = can be' flow control valve 'flow control valve has individual differences (accuracy changes) in control, so' in ' Use flow pack

7054-2918-P71-ptc Page 12 4 4〇92 6 V. Explained in detail (1〇) Because of the relationship between flow rate and mixing concentration, set 1 2a, 1 3a to make the gas mixing situation non-linear, the gas at the point of use The amount of use changes every time due to the method. The mixing concentration also becomes variable with the amount of use (flow rate change). It is difficult to mix the gas by the gas mixing method using the mixing ratio of the coarse mixing pipe 2 a and 10 a. When the concentration is controlled to a fixed value. In view of this situation, in the objective of this embodiment, it is advantageous to use the generated amount of the rough mixing pipe 2a and 1 Oa and use a commensurate mixed gas as the approximate set concentration (assuming that the concentration is slightly different from the set concentration). The deviation of the set concentration is corrected by the fine adjustment of the mixing pipe 2b, 1 Ob of the small flow pipe. The gas concentration detector / sensor 15 detects the concentration of the mixed gas discharged from the mixer 5 (diborane gas Concentration), the detection signal is supplied to the two-wheel-out regulator 31. The two-output regulator 31 will use the set mixing ratio based on the high-concentration diborane gas and hydrogen. The mixing concentration value of the drum will be used as the set value box for the final memory. The two-output regulator 31 is based on the gas. The amount of mixed gas detected by the amount detection sensor ^, the data of the set mixed concentration read from the memory, and the amount of the mixed gas detected by the gas concentration sensor 15 Unexpectedly, PID calculation is used to calculate the deviation of the mixed gas detection concentration to zero. The gas compensation amount of the additional amount of high concentration diborane gas and hydrogen is required. For example, in the mixed gas detection concentration (diboron Alkane gas concentration) Relative to the set mixed concentration, calculate the gas compensation amount of hydrogen used to set the mixed concentration. Conversely, when the mixed gas detection concentration is low, calculate the gas compensation amount of diborane gas concentration. The two-wheel-out regulator 31 is also used

4 40 92 6 V. Description of the invention (11) '^^ --- To obtain the gas compensation amount of the flow control valve i 2 b, No., supply the corresponding flow control 阙 12b, l3b. After receiving the valve opening control signal, the opening control letter of b will perform the variable opening and closing of the valve as the opening amount of the flow. The valve 1 is required to be 2b, and the pipeline 2b is required to supply the mixer 5 with additional gas compensation. The second is to fine-tune the mixture to mix the gas with a low concentration of the mixed cry 5 within the mix * Qiao / Chen degrees diborane. 〇 ”in this mouth is modified to set the mixing requirements ^ 3 3 ϊ Γ open valve control # after the number 'if the flow control valve 13b is changed between the results of the variable drive results, through the micro-mixer 5 gas The compensation amount of hydrogen is corrected to the mixed gas in the mouthpiece 5 in the mouth part 5 to a gas with a set concentration. It is explained that the mixture of diborane gas used in the system of FIG. 2 is used for _ # using the extension The resistivity control process of the epitaxial film of the device is in the state that the four high-pressure vessels 9 that supply power to the boron and gas are open, and the high-concentration diborane gas of 1 000 ppm sent from the high-pressure vessel 9 (diluted with hydrogen) The high-concentration diborane gas) merges through the piping line 2 and passes through the 2 coarse mixing line 2a and is introduced into the mixer 5. However, the source of hydrogen from the hydrogen is introduced through the piping pipeline 10, through the rough mixing pipeline 1 Oa, and is introduced into the mixing 35 5 ° At this time, the 'Li Zhou gas amount detection sensor 1 8 detects from the mixer 5 The amount (flow rate) of the high-concentration diborane gas and hydrogen mixed gas supplied to the ^ buyen device is used as the value of the gas usage amount at the point of use, using a gas mixing control device (calculation control section 21, control drive signal output section) 22 and flow control split 1 2a, 1 3a) Control flow control according to the ratio of the set mixing ratio

Page 14 4-40 92 6

V. Description of the invention ¢ 12) The valve opening amounts of the devices 12a and 13a are such that the same amount of mixed gas. As a result, the gas is mixed and controlled at a predetermined mixing ratio and then supplied to the epitaxial apparatus. The production volume and the detected gas usage are mixed at the point of use.

On the other hand, the Lizhou gas concentration debt sensor 15 detects the concentration of the mixed gas discharged from the mixer 5. When the detected concentration is higher than the set concentration, the gas concentration fine-tuning control device (two-round out regulator) is used. 31 and flow control valve 1 2b, 1 3b) By controlling the flow control valve 丨 3b, add hydrogen (trace hydrogen) in the mixer 5 introduced from the fine-tuning mixing pipe i 0b to correct the concentration deviation to mix the gas The density is corrected to set the mixed density. 〃 Similarly, when the detected concentration is lower than the set concentration, the gas concentration fine-tuning control device is used to control the flow control valve i 2b to add a high-concentration diboron to the mixer 5 to correct the concentration deviation by the fine-tuning mixing pipe 2b. The alkane gas' corrects the mixed concentration of the gas to the set mixed concentration. _Set the mixed concentration of mixed gas in the mixer buffer 16 to equalize the pressure 'use the monitoring gas concentration detection sensor 1 7 to detect the mixed gas concentration in the pressure equilibrium state' in the monitoring gas concentration detection The sensor sensor 7 means that when an abnormality occurs in the measured concentration, the safety operation such as stopping the system operation is performed. The mixed gas with the set concentration is supplied to the buffer container 3 through the mixer buffer 6; however, a pressure maintaining valve 20 is provided on the front side of the buffer container 3, and when the set pressure is exceeded, The pressure '19 to discharge the excess amount out of the system 'keeps the buffer container 3 always at the set pressure. That is, the finely-adjusted mixing lines 2b and 1 Ob are additionally supplied with a gas having an adjusted concentration.

Page 15 4. 4 Ο 9 2 δ _________________ __ 5. In the description of the invention (13), because the mixed gas generated in the mixer 5 is more than the amount used, the pressure of the mixed gas exceeds the set pressure. At this time, the mixed gas that has been added to the system through the degassing line 19 is discarded to the outside of the system, and the buffer tank 3 for supply to the epitaxial device is adjusted to a mixed gas having a set pressure. In addition, the gas that was discarded outside the system became a waste of resources, but because the additional gas supply for concentration adjustment was provided by the fine-tuning mixing pipes 2b and 10b, the amount of gas that was discarded was a trace amount, and the fine-tuning mixing pipe was not used 2b, 1 Compared with the case of concentration adjustment, the amount of discarded gas is greatly reduced, and resources can be effectively used. If according to this embodiment ', the structure can be diluted to produce a high-concentration ethylene oxide gas and then supplied to the epitaxial device, the high-pressure container 9 containing a high-concentration diborane gas of 1000 ppm can be used as a supply source of the gas at the second hospital. Therefore, compared with the case of using the high-pressure vessel 1 containing a thin diborane gas of 1000 ppm as shown in FIG. 3 of the conventional example, the consumption per unit time of the diborane gas in the high-pressure vessel can be reduced. The quantity can avoid the replacement of the diborane gas high-pressure container during the continuous operation of the device, and can solve the problem of the conventional example accompanying the high-pressure container replacement. In particular, in this embodiment, since a plurality (4) of high-pressure vessels 9 of high-concentration ethyl sintering gas are used at the same time, the period until the high-pressure vessels 9 are replaced can be sufficiently extended. Furthermore, by using a plurality of (4) high-pressure vessels 9 having high-concentration diborane gas at the same time, the influence of fluctuations in the concentration of the diborane gas between the high-pressure vessels 9 can be alleviated. That is, in the case of replacing or switching the high-pressure vessels 9 using diborane gas one by one, the concentration changes immediately after the high-pressure vessels 9 are replaced (switched). However, by using a plurality of high-pressure vessels 9 simultaneously, the gas sent out

Page 16 440 92 6 V. Description of the invention (14) ---- The wave length becomes a concentration that roughly averages the concentration of each high-pressure vessel. Therefore, the change in the gas concentration before and after the high-pressure container is replaced can be made small, and the change in the gas concentration accompanying the replacement of the pressure container 9 can be eased. In addition, as described above, since the frequency of replacing the high-pressure container 9 can be reduced, the cost of the high-pressure container can be greatly reduced. In particular, in the present market, the difference in gas concentration has almost no effect on the price of diborane gas. The benefits of reducing the cost of the high-pressure vessel are large. 'Furthermore, in this embodiment, the gas concentration detection sensor 15 is disposed upstream of the mixer buffer 6 immediately after the mixer 5 and before the pressure is equalized.' Mixed by the mixer 5 for instant detection ' After the concentration of the generated mixed gas changes, the deviation from the set concentration can be corrected quickly. In particular, in this embodiment, since the gas concentration detection sensor is constituted by an infrared absorption type sensor, the detection accuracy of the detection response can be improved. Since the gas concentration detection sensor 17 for monitoring and the gas amount detection sensor 18 are provided downstream of the mixer buffer 16, the gas concentration detection sensor 17 for monitoring can be accurately used. The equilibrium gas concentration is detected, and the gas quantity detection sensor 18 can accurately detect the gas quantity not affected by the pressure fluctuation. In addition, the present invention is not limited to the above-mentioned embodiments, and various other embodiments may be adopted. For example, in the above embodiment, the piping pipeline 2 is branched to form a coarse mixing pipeline 2a and a fine-tuned mixing pipeline 2b. However, for example, the piping pipeline 2 is configured as a pipeline of the coarse mixing pipeline 2a. The side of the high-pressure vessel 9 and the mixer 5 are connected to form a communication pipe to form a fine-tuned mixing pipeline 2 b,

Page 1 * 7 4 4〇 92 6

The pipeline & 2 b may be formed by a separate pipeline connecting the high pressure vessel 9 side and the mixer 5. Similarly, in the above-mentioned embodiment, the piping pipe 10 is branched to form a coarse mixing pipe 10a and a fine-tuned mixing pipe 10a. However, for example, the piping pipe 10 is used as a rough mixing pipe 丨 0a. In addition, a piping that connects the oxygen supply source and the mixer 5 to form a fine-tuned mixing pipeline 1 Ob 'is formed by a separate pipeline connecting the hydrogen supply source and the mixer 5 to form a pipeline 1 Q a , 1 0 b is also available. However, 'by branching the rough mixing official circuit and fine-tuning the mixing pipeline as in this embodiment', the simplification of the pipeline can be achieved, and the cost savings associated with the savings of the existing pipeline components can not only be neatly organized. The piping also has the effect of making piping construction easy.

Also in the above-mentioned embodiment, the tritium gas of the second gas is diluted and mixed with the high concentration of 100 ppm of the first gas of the diboron compound gas to produce a thin diborane gas of 100 ppra used at the point of use. However, pure gas in the first gas system may also be used. Diluted gas in the second gas system may also be used. Also in this example, the second gas is used as a gas for diluting the first gas (diluent is the base gas of the diborane gas that is the main doping gas), but the components of the first gas and the second gas are not limited In this way, for example, a gas having a component not included in the first gas may be used as the second gas. Moreover, in the above-mentioned embodiment, 'the use of a diborane gas concentration of 100 ppm in a high-concentration diborane gas', but the concentration is other than 100 ppm. Of course, it is also possible to use diboron in this patent specification. An alkane gas concentration of 5,000 ppm or more is defined as a high-concentration diborane gas D. Also in the above embodiment, the mixed supply of the first gas and the second gas was explained, but the present invention is applicable to more than three kinds of gases Mixed offering

Page 18

Amend

Case No. 89101RU Invention Description (16) given. In this case, use a pipe with a coarse mixing pipe and a fine-tuning mixing pipe to connect the supply sources of various gases. As in the case of mixing the two gases, use the coarse mixing pipe to control the flow according to the ratio of the mixing ratio. Use the fine-tuning mixing line to correct the deviation from the set concentration. Further, in the above-mentioned embodiment, the infrared absorption sensor is used to constitute the I gas concentration detection sensor 15, but, for example, another concentration detection device such as a gas chromatograph may be used. Also in the above-mentioned embodiment, in the case where the deviation of the mixed gas concentration (diborane gas concentration) is fine-tuned by using the fine-tuning mixing pipe 2 b0 乜, the gas of the sensor 18 is used to adjust the amount of shake. Information, but it is also possible to correct the deviation of the mixed gas concentration without using the detection information of the 玄 xuan gas amount detection sensor 18. In this case, the memory of the two-wheel-out regulator 3 丨 is supplied in advance as the deviation from the set mixing concentration becomes larger, increasing the relationship between the deviation of the gas compensation amount (additional gas supply amount) and the gas compensation amount. Then, in this state, the two-output regulator 31 compares the mixed gas detection concentration detected by the gas concentration detection sensor 15 with the set mixed concentration, and then 'finds the deviation of the mixed gas detection concentration with respect to the set mixed concentration. , I use p I 〇 to calculate the gas compensation amount according to the amount of deviation according to the relationship data (when the deviation amount is positive, the gas compensation amount of hydrogen is calculated, when the deviation amount is negative, the high-concentration diborane gas is calculated. Compensation amount), the valve opening control signal obtained for the gas compensation amount of high-concentration diborane gas or hydrogen is supplied to the corresponding flow control valves 1 2 b, 1 3 b, and the flow control valve is performed in the same manner as in the above embodiment. The 1 2b, 1 3b valve opening drive can correct the deviation of the mixed gas concentration | to zero. !

Page 19-A 〇9 2 β 5. Description of the invention (17) If this control mode is adopted, the deviation of the concentration of the mixed gas is corrected, because the compensation amount of the additional gas is also reduced as the deflection amount becomes smaller. The control of deviation correction 'converges the deviation amount to zero in a short period of time, and the deviation amount becomes zero in the future,' which can maintain a stable supply of a mixed gas with a set mixed concentration, and The epoch-making effect of high-precision gas concentration adjustment due to detection errors and other influences. Also, in FIG. 2 of the above embodiment, four high-pressure vessels 9 of high-concentration diboron burning gas are bundled together, but the high-pressure vessels 9 of high-concentration diborane gas can also be used as a group in structure. You can also switch one by one interactively. In addition, when gas with different concentration is needed at the point of use, it can be adapted by adding it again—the structure of the part A surrounded by the dotted line in FIG. 2 (the structure of the part B enclosed by the dotted line in FIG. 2 is shared). The resistivity control of the epitaxial film is clear in the above-mentioned embodiment. However, the present invention is of course applicable to the production of δ gas in other semiconductor manufacturing fields. It is also applicable to the mixed gas field other than semiconductor manufacturing. μ Effects of the invention The present invention uses a coarse mixing pipe and a fine-tuning mixing pipe to form a gas mixing source from the first and second gas supply sources to the gas mixing supply pipe. Set the concentration to approximately the same; ::: Mix the amount of gas produced at the point of use (and the amount of gas that is used only at the point of use). You can use the fine-tuned mixing pipeline to correct the relative concentration deviation. Therefore, by using the mixing ratio control: What is the pipeline of the two systems of the fine-tuning pipeline, and the circuit & 峪 is used as a structure for generating a mixed gas?

Page 20 f 440926 V. Description of the invention (18) For example, compared with the case where a mixed gas is generated after the flow control of the first gas and the second gas using only one system pipeline, the concentration control accuracy becomes very high. High, it is possible to obtain the effect of stably supplying a mixed gas having a fixed concentration with high reliability. In particular, in the present invention, because the gas mixing control device is used to mix the first gas and the second gas according to the distribution ratio of the set gas mixing ratio, the amount of gas used at the point of use is generated. As described above, the mixed concentration becomes It is approximately equal to the set mixing density. Therefore, if the control device on the side of the fine-tuning mixing pipeline that repairs small deviations in concentration is also malfunctioning, the amount of gas supplied to the gas mixer from the fine-tuning mixing pipeline is small, which can prevent the concentration at the point of use from significantly deviating from the set mixing concentration Poor gas. In addition, due to the present invention, the concentration of the mixed gas discharged from the gas mixer can be detected by the mixed concentration detection device, and the change of the mixed concentration can be detected instantaneously, and the concentration deviation can be instantly adjusted based on the detected value by the gas concentration fine-tuning control device. The correction control can improve the accuracy of the correction of the gas concentration deviation. Especially by using the infrared absorption sensor to form a mixed concentration detection device, not only the response of the concentration detection can be improved, but also because of the mixing used for detection. The gas (mixed gas in contact with the infrared absorption sensor) will not be discarded at the point of use. There is no waste of gas utilization, and the effect of fully improving the utilization efficiency of the mixed gas can be obtained. Further, in the present invention, a high-concentration diborane gas (high-concentration doped gas) is used as the first gas, and a hydrogen gas (pure gas for dilution) is used as the second gas, and the high-concentration diborane gas and hydrogen are mixed. Diluted diborane gas is supplied to the epitaxial device to control the resistivity of the epitaxial film.

'40 92 6. I · V. Description of the invention (19) In case, can a container (such as a high-pressure container) be used for diborane gas supply? Nongdu B's burning gas' weekly nitrogen dilutes the south-concentration ethane gas and supplies it to the point of use, and it is conventionally supplied from a high-pressure vessel to an epitaxial device and at a thin concentration of B at the point of use. Compared with the case of borane gas, the present invention, which can adopt a method of supplying a high-concentration diborane gas from a high-pressure vessel to a gas mixer, can greatly reduce the consumption of diborane gas per unit time in the high-pressure vessel. Therefore, by adopting the structure of the present invention, it is not necessary to replace the high-pressure vessel of diborane gas during the continuous operation of the epitaxial device, which can solve the obstacle to resistivity due to the change in the concentration of diborane gas immediately after replacing the high-pressure vessel. ) Known problems caused by replacement of high pressure vessels under control. Brief Description of the Drawings Fig. 1 is a structural explanatory diagram of an embodiment of a gas mixing and supplying device applicable to the gas mixing and supplying method of the present invention. FIG. 2 is an explanatory diagram of a diborane gas supply system including the gas mixed supply device shown in FIG. 1. FIG. Fig. 3 is an explanatory diagram of a conventional example of a diborane gas supply system. Explanation of symbols 2 a, 1 0 a coarse mixing line \ 2b, 1 Ob fine adjustment mixing line 5 mixer (gas mixer) 12a, 13a flow control device (mass flow controller) 12b, 13b flow control valve 1 5 gas Density detection sensor

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Claims (1)

4 40 92 6 VI. Scope of patent application 1. A gas mixing and supply method, a 罔 gas mixer mixes a first gas supplied from a first gas supply source and a second gas supplied from a second gas supply source, and supplies it for use Point the mixed gas of the first gas and the second gas, which is characterized in that the gas from the first and second gas supply sources to the gas mixer is formed by the pipelines of the coarse mixing pipeline and the fine-tuning mixing pipeline. Supply line, using this coarse mixing line to supply the first gas and the second gas that are proportional to the amount of gas mixer and the amount of gas used at the point of use in accordance with the ratio of the set mixing ratio, to produce the used amount of coarse mixed gas, and use this fine adjustment The adjustment of the mixing pipeline should eliminate the supply amount of the first gas and the second gas whose deviation of the coarse mixed gas concentration from the set mixed concentration. 2. A gas mixed supply device, comprising: mixing a first gas supplied from a supply source of a first gas and a second gas supplied from a supply source of a second gas; The gas mixer of gas is composed of two systems of a coarse mixing pipeline and a fine-tuning mixing pipeline. The gas supply pipeline is formed from each of the first and second gas supply sources to the gas mixer. 3. For example, the gas mixing supply device in the scope of patent application No. 2 includes: a gas amount detection sensor that detects the amount of mixed gas used at the point of use; and a gas mixing control device that will use the amount of gas The amount of gas detected by the detection sensor is used as the set value of the gas generation amount. 440926 6. Scope of patent application The distribution ratio of the mixing ratio is controlled by the supply amount distribution of the first gas and the second gas supplied through the rough mixing pipeline so that the mixing amount becomes the set value of the gas generation amount. 4. If the gas mixing and supplying device of the second or third item of the patent application scope includes: a mixing concentration detection device that detects the mixing concentration of the mixed gas discharged from the gas mixer; and a gas concentration fine-tuning control device for detection After the deviation of the mixed concentration with respect to the set mixed concentration determined according to the set gas mixing ratio of the first gas and the second gas, control is performed between the first gas and the second gas supplied to the gas mixer via the fine-tuned mixing pipeline that should eliminate the deviation. Supply amount. 5. For example, the gas mixing supply device in the scope of patent application No. 4, wherein the mixed concentration detection device is an infrared absorption type gas concentration detection sensor. 6. If the gas mixing and supplying device of item 2 or 3 of the scope of patent application, the first gas system is a high-concentration doping gas, and the second gas system is a pure gas for diluting the doping gas. 7. The gas mixing and supplying device according to item 4 of the scope of the patent application, wherein the first gas system is a high-concentration doped gas, and the second gas system is a pure gas for diluting the doping gas. 8. The gas mixing and supply device according to item 5 of the scope of patent application, wherein the first gas system is a high-concentration doping gas, and the second gas system is a pure gas for diluting the doping gas. Page 25