TWI721018B - Raw material gas supply device, raw material gas supply method and storage medium - Google Patents

Abstract

Provide a method when the solid raw material is gasified When the raw material gas of the gas is supplied to the film formation processing section, it is a technology to stabilize the supply amount of the gasified raw material.

It is used to supply carrier gas to the raw material container (14) The carrier gas supply path (12) is provided with MFC1, and the raw gas supply path (32) is provided with MFM3. In addition, an MFC2 is provided in the dilution gas supply path (22) for supplying the dilution gas to the source gas supply path (32). Then, calculate the compensation value obtained by subtracting the total value of the MFC1 measurement value and the MFC2 measurement value from the MFM3 measurement value, and then subtract the total value of the MFC1 measurement value and the MFC2 measurement value from the MFM3 measurement value The obtained value is subtracted from the compensation value to obtain the actual measured value of the flow rate of the raw material. Then, in accordance with the difference between the actual measured value of the raw material flow rate and the target value of the raw material, the setting value of MFC1 is adjusted to adjust the flow rate of the carrier gas, and the amount of raw material contained in the raw material gas is adjusted.

Description

Raw material gas supply device, raw material gas supply method and storage medium

The present invention relates to a technique of supplying the vaporized raw material and the carrier gas to the film formation processing section.

As a kind of film forming process in the semiconductor manufacturing process, there are ALD (Atomic Layer Deposition: Atomic Layer Deposition) which alternately supplies the raw material gas and the reactive gas for oxidizing, nitriding or reducing the raw material gas, or putting the raw material gas in the gas phase. CVD (Chemical Vapor Deposition: Chemical Vapor Deposition) that decomposes or reacts with reactive gas. As the raw material gas used in such a film formation process, in order to increase the density of the crystals after film formation and minimize the amount of impurities incorporated into the substrate, a gas that sublimes the raw material is used, for example, for the A film-forming device that uses ALD to form the electro-body film.

In such a film forming apparatus, a raw material container containing a solid raw material or a liquid raw material is heated, and the raw material is vaporized (sublimed) to obtain a gas of the raw material. Then, a carrier gas is supplied into the aforementioned raw material container, and by this carrier gas, the raw material is supplied to the processing container. In this way, the raw material gas is a mixture of carrier gas and gas raw materials. When you want to control the film formation in the semiconductor In the case of bulk wafer (hereinafter referred to as "wafer") film thickness or film quality, etc., the vaporization amount of the raw material (the flow rate of the raw material contained in the raw gas) must be adjusted correctly.

However, the amount of vaporization of the raw material in the raw material container varies with the filling amount of the raw material, and when the raw material is solid, it also changes due to the bias of the raw material in the raw material container or the change in grain size. In addition, when the raw material is solid, the heat will be taken away when the raw material is sublimated ("vaporization" in this case) and the temperature in the raw material container will be lowered. If it is a solid raw material, it will not occur in the raw material container. Convection, so the temperature distribution in the raw material container tends to be biased. Therefore, the amount of vaporization of the raw material tends to become unstable.

In recent years, with the miniaturization of wiring patterns formed on wafers, there is a desire for a method to achieve stability of film thickness or film quality. In addition, in the ALD method, the supply time of the raw material gas is short, but in this case, it is necessary to explore a method that can control the supply amount of the raw material to a set value.

Patent Document 1 describes a method for detecting the total mass flow rate of non-evaporated gas in the system when the carrier gas is fed into the liquid raw material evaporation part and the buffer gas is introduced into the system, and the control is such that the total mass flow rate becomes constant. Value technology. However, the error of each flowmeter has not been considered.

In addition, in the raw material gas supply device of Patent Document 2, the mass flow meter is calibrated by the flow rate of the carrier gas. Therefore, when the flow rate of the carrier gas is set to the set value by the mass flow controller, the mass flow meter The measured flow rate is the flow rate obtained by subtracting the set value of the carrier gas flow rate, That is, it represents the amount of sublimation of the raw material when the set value of the flow rate of the carrier gas is zero. In view of this, in order to obtain the sublimation amount of the raw material, a technique of multiplying the value obtained by subtracting the set value of the flow rate of the carrier gas from the measured flow rate of the mass flowmeter by the proportional counting is described. However, this does not solve the problem of the present invention.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 5-305228 A

[Patent Document 2] JP 2014-145115 A

The present invention was developed based on such a reason, and its purpose is to provide a method for vaporizing the raw material when the raw material gas containing the gas obtained by gasifying the solid or liquid raw material is supplied to the film formation processing section. Technology with stable supply.

The raw material gas supply device of the present invention vaporizes the solid or liquid raw material in the raw material container, and supplies it together with the carrier gas as the raw material gas through the raw material gas supply path to the substrate for film processing. The raw material gas supply device of the membrane processing section is characterized by comprising: a carrier gas supply path for supplying carrier gas to the raw material container; a bypass passage that branches from the carrier gas supply path to avoid the raw material container and is connected to the raw material Gas supply path; diluent gas supply path, connected to the raw gas supply path downstream of the connection part of the bypass passage, used for confluence of diluent gas to raw gas; first mass flow controller and second mass flow The controller is respectively connected to the carrier gas supply path and the dilution gas supply path; the mass flow meter is arranged on the downstream side of the confluence of the dilution gas supply path in the raw gas supply path; the switching mechanism is connected to the raw material container The bypass passages switch between the carrier gas passage from the carrier gas supply route to the raw gas supply route; the control unit adjusts the measured values of the flow rates of the first mass flow controller, the second mass flow controller, and the mass flow meter Set as m1, m2, and m3, respectively, and execute: The first step is to circulate carrier gas and diluent gas while switching the carrier gas path to the bypass path side to obtain {m3-(m1+m2)} The calculated value of is the compensation value; and in the second step, in the state where the carrier gas passage is switched to the raw material container side, the carrier gas and diluent gas are circulated to obtain the calculated value of {m3-(m1+m2)}, From this calculation value, subtract the aforementioned compensation value to obtain the actual measured value of the flow rate of the raw material, and obtain Take the difference between the target value of the raw material flow rate and the aforementioned actual measurement value; and the third step is to adjust the setting of the first mass flow controller based on the aforementioned difference value and the relationship between the increase or decrease in the flow rate of the raw material and the increase or decrease in the carrier gas Value so that the flow rate of the raw material becomes the target value.

The raw material gas supply method of the present invention vaporizes the solid or liquid raw material in the raw material container, and supplies the raw material to the film forming processing section for processing the substrate into the film through the raw material gas supply path as the raw material gas together with the carrier gas The gas supply method is characterized by having: a carrier gas supply path for supplying carrier gas to the raw material container; and a bypass path branched from the carrier gas supply path to avoid the raw material container and connected to the raw material gas supply Path; and the dilution gas supply path, connected to the downstream side of the raw gas supply path than the connection part of the bypass passage, for converging the dilution gas to the raw gas; and the first mass flow controller and the second mass flow The controller is respectively connected to the carrier gas supply path and the dilution gas supply path; and a mass flow meter, which is provided on the downstream side of the confluence of the dilution gas supply path among the raw gas supply paths; and a switching mechanism, in the raw material container The carrier gas path that switches between the inner and the bypass path from the carrier gas supply path to the raw gas supply path; the raw gas supply device includes: the first mass flow controller, the second mass flow controller, and the mass flow The measured values of the flow rate of the meter are respectively set as m1, m2 and m3, and in the state where the aforementioned carrier gas passage is switched to the bypass passage side, the carrier gas and diluent gas are passed through to obtain {m3-(m1+m2) } The calculation value of is also the process of the compensation value; in the state where the aforementioned carrier gas path is switched to the raw material container side, the carrier gas and diluent gas are circulated to obtain the calculation value of {m3-(m1+m2)}, and then the calculation value The process of obtaining the actual measured value of the flow rate of the raw material by subtracting the aforementioned compensation value, and obtaining the difference value between the target value of the raw material flow rate and the aforementioned actual measured value; based on the aforementioned difference value, and the increase or decrease of the flow rate of the raw material and the carrier gas The relationship between the increase and decrease is the process of adjusting the setting value of the first mass flow controller so that the flow rate of the raw material becomes the target value.

The memory medium of the present invention is a memory medium with a computer program stored therein. The computer program is used to vaporize the solid or liquid raw material in the raw material container, and the carrier gas is used as the raw material gas to be supplied to the raw material through the raw material gas supply path. The raw material gas supply device of the film forming processing section of the film processing of the substrate, and the memory medium is characterized in that:

The aforementioned computer program is programmed with a group of steps to execute the aforementioned raw gas supply method.

In the present invention, when the solid or liquid raw material in the raw material container is vaporized, and the carrier gas is supplied as the raw material gas to the film formation processing section through the raw material gas supply path, the carrier gas supply path and the raw material gas supply path are respectively provided with 1 Mass flow controller and mass flow meter. In addition, a second mass flow controller is provided in the dilution gas supply path for supplying the dilution gas to the source gas supply path. Then, find from the mass flow The compensation value obtained by subtracting the total value of the measurement value of the first mass flow controller and the measurement value of the second mass flow controller from the measurement value of the meter. In addition, when the source gas is supplied to the film formation processing section, the value obtained by subtracting the total value of the measurement value of the first mass flow controller and the measurement value of the second mass flow controller from the measurement value of the mass flow meter is subtracted Calculate the actual measured value of the flow rate of the raw material by removing the compensation value. Then, in accordance with the difference between the actual measured value of the raw material flow rate and the target value of the raw material flow rate, the setting value of the first mass flow controller is adjusted to adjust the flow rate of the carrier gas, and the amount of the raw material contained in the raw material gas is adjusted. Therefore, the individual error of each measuring device is eliminated, the actual measured value of the flow rate of the raw material can be obtained with high precision, and the concentration of the raw material gas (the flow rate of the raw material) supplied to the film formation processing section is stabilized.

1‧‧‧MFM

2, 3‧‧‧MFC

7‧‧‧Bypass

9‧‧‧Control Department

12‧‧‧Carrier gas supply path

14‧‧‧Raw Material Container

22‧‧‧Diluent gas supply path

32‧‧‧Gas supply path

40‧‧‧Vacuum Processing Department

44‧‧‧Vacuum Exhaust Department

47‧‧‧Pressure regulating valve

48‧‧‧Valve

100‧‧‧wafer

V1~V7‧‧‧Valve

[Fig. 1] A schematic view of the overall configuration of a film forming apparatus using the raw material gas supply apparatus of the present invention.

[Fig. 2] A configuration diagram of the control unit provided in the source gas supply unit.

[Fig. 3] A schematic flowchart of the adjustment process of the supply amount of the raw material in the raw gas supply part.

[Fig. 4] A schematic characteristic diagram of the difference between the measured value of the MFM and the total value of the set value of the first MFC and the set value of the second MFC.

[Fig. 5] A schematic timing chart of the opening and closing of the valve and the time change of the flow rate of the raw material supplied from the raw material gas supply part.

[Figure 6] A schematic characteristic diagram of an example of measured values measured by MFM.

[Fig. 7] A schematic characteristic diagram of the increase and decrease of the flow rate of the carrier gas and the increase and decrease of the amount of the raw material.

[Figure 8] A schematic explanatory diagram of the actual measured value of the flow rate of the raw material under the film forming process of each wafer.

[Fig. 9] A configuration diagram of a control unit provided in a source gas supply unit in another example of the embodiment of the present invention.

[Fig. 10] A schematic explanatory diagram of the treatment recipe.

[Fig. 11] A schematic explanatory diagram of the format for formula calculation.

[Fig. 12] A schematic explanatory diagram of the formula for calculation.

[Figure 13] Schematic characteristic diagram of the relationship between carrier gas flow rate and compensation value.

[Figure 14] A schematic characteristic diagram of the relationship between the total flow rate of the carrier gas flow rate and the dilution gas flow rate and the compensation value.

A configuration example in which the raw material gas supply device of the present invention is applied to a film forming device will be described. As shown in FIG. 1, the film forming apparatus includes a film forming processing section 40 for performing film forming processing on a substrate, that is, a wafer 100 by the ALD method. Here, the film forming processing section 40 includes a raw material for supplying raw material gas. A raw material gas supply unit 10 constituted by a gas supply device. In addition, in the specification, a gas obtained by combining a carrier gas and a raw material flowing (sublimed) with the carrier gas is referred to as a raw material gas.

The raw material gas supply unit 10 includes a raw material container 14 _{containing WCl 6 containing raw materials.} The raw material container 14 is a container for accommodating WCl ₆ which is solid at room temperature, and is covered by a jacket-like heating part 13 provided with a resistance heating element. The raw material container 14 is configured to increase or decrease the amount of power supplied from a power supply unit not shown in the figure based on the temperature of the gas phase part in the raw material container 14 detected by a temperature detection unit not shown, thereby enabling adjustment The temperature in the raw material container 14. The set temperature of the heating part 13 is set to a temperature _{within a range where the solid raw material will sublime and the WCl 6} will not decompose, for example, 160°C.

In the gas phase portion on the upper side of the solid raw material in the raw material container 14, the downstream end of the carrier gas supply path 12 and the upstream end of the raw material gas supply path 32 are inserted. At the upstream end of the carrier gas supply path 12, a carrier gas _{supply source 11 is provided as a supply source of carrier gas such as N 2} gas. In the carrier gas supply path 12, a first mass flow controller is inserted in order from the upstream side. (MFC) 1, valve V3, valve V2.

On the other hand, in the raw material gas supply path 32, a valve V4, a valve V5, a mass flow meter (MFM) 3 and a valve V1 which are a flow measurement unit are provided from the upstream side. In the figure, 8 is a pressure gauge for measuring the pressure of the gas supplied from the source gas supply path 32. In the vicinity of the downstream end of the source gas supply path 32, a reaction gas or replacement gas described later also flows, so it is indicated as a gas supply path 45. In addition, on the upstream side of the MFM 3 in the source gas supply path 32, the downstream end of the dilution gas supply path 22 for supplying the dilution gas merges. At the upstream end of the dilution gas supply path 22, a dilution gas supply source 21 that is a supply source of _{a dilution gas such as N 2 gas is provided.} In the dilution gas supply path 22, a second mass flow controller (MFC) 2 and a valve V6 are inserted from the upstream side. The valve V2 and the valve V3 in the carrier gas supply path 12 and the valve V4 and the valve V5 in the material gas supply path 32 are connected by a bypass passage 7 provided with a valve V7. Valves V2, V4, and V7 are equivalent to switching mechanisms.

Next, the film formation processing unit 40 will be described. For example, the film formation processing unit 40 in the vacuum container 41 includes a mounting table 42 that holds the wafer 100 horizontally and is equipped with a heater (not shown), and a gas introduction unit that introduces raw material gas and the like into the vacuum container 41 43. A gas supply path 45 is connected to the gas introduction part 43, and the gas supplied from the source gas supply part 10 is configured to pass through the gas introduction part and be supplied into the vacuum container 41. In addition, the vacuum container 41 is connected to a vacuum exhaust unit 44 through an exhaust pipe 46. The exhaust pipe 46 is provided with a pressure adjustment valve 47 and a valve 48 that constitute a pressure adjustment unit 94 that adjusts the pressure in the film formation processing unit 40.

In addition, in the gas supply path 45, a reaction gas supply pipe 50 for supplying a reaction gas that reacts with the raw material gas and a replacement gas supply pipe 56 for supplying a replacement gas merge. The other end side of the reaction gas supply pipe 50 is branched into an _{H 2} gas supply pipe 54 connected to a supply source 52 of a _{reaction gas such as hydrogen (H 2} ) gas, and connected to a supply of inert gas such as nitrogen (N ₂ ) gas Source 53 inert gas supply pipe 51. In addition, the other end side of the replacement gas supply pipe 56 is connected to a supply source 55 of a _{replacement gas such as N 2 gas.} V50, V51, V54, and V56 in the figure are valves provided in the reaction gas supply pipe 50, the inert gas supply pipe 51, the H ₂ gas supply pipe 54, and the replacement gas supply pipe 56, respectively.

As will be described later, in the film formation of the W (tungsten) film in the film formation processing section 40, a _{raw material gas containing WCl 6} and a reactive gas that is a H ₂ gas system are alternately supplied, and the raw material gas and During the supply of the reaction gas, a replacement gas is supplied in order to replace the environment in the vacuum container 41. In this way, the raw material gas is intermittently supplied to the film formation processing section 40 during the alternate and repetitive supply period and the rest period, and the supply control of the raw material gas is performed by controlling the ON and OFF of the valve V1. This valve V1 is configured to be switched and controlled by a control unit 9 described later. "ON" means a state in which the valve V1 is opened, and "OFF" means a state in which the valve V1 is closed.

The raw material gas supply unit 10 is provided with a control unit 9. As shown in FIG. 2, the control unit 9 includes a CPU 91, a program storage unit 92, and a memory 93 that stores a recipe for the film formation process performed on the wafer 100. In addition, 90 in the figure is a bus bar. In addition, the control unit 9 is connected to a pressure adjustment unit 94 connected to the respective valve groups V1 to V7, MFC1, MFC2, MFM3, and the film formation processing unit 40. In addition, the control unit 9 is connected to a host computer 99. For example, the recipe for the film formation process of a lot of wafers 100 carried in the film formation apparatus is sent out from the host computer 99 and stored in the memory 93.

The processing recipe is information that the film forming process of the wafer 100 set one by one for each lot is created together with the processing conditions. As the processing conditions, the process pressure, the supply of the gas supplied to the film formation processing unit 40 in the ALD method, the time of stoppage, the flow rate of the source gas, and the like can be mentioned. To briefly explain the ALD method, first, the raw material gas, ie, WCl ₆ gas, is supplied, for example, for 1 second, and the valve V1 is closed, so that the WCl _{6 is} adsorbed on the surface of the wafer 100. Next, a replacement gas (N ₂ gas) is supplied to the vacuum container 41, and the inside of the vacuum container 41 is replaced. Next, the reaction gas (H ₂ gas) and the diluent gas (N ₂ gas) are supplied to the vacuum vessel 41 together. Then, by hydrolysis and dechlorination reactions, the atomic film of W (tungsten) film is formed on the wafer 100 surface. After that, the replacement gas is supplied to the vacuum container 41, and the vacuum container 41 is replaced. In this way, in the vacuum vessel 41, the cycle of supplying _{the raw material gas containing WCl 6} →substitution gas→reaction gas→substitution gas is repeated multiple times, thereby forming the W film.

The ALD method executes a cycle of supplying raw material gas, replacement gas, reaction gas, and replacement gas in this order multiple times. Therefore, the cycle formula is defined to determine the timing of the ON signal and the OFF signal. For example, the supply/cut of the raw material gas is performed by the valve V1, so the period from the ON signal of the valve V1 to the OFF signal is the supply time of the raw gas, and the period from the OFF signal of the valve V1 to the ON signal It is the resting period of the raw material gas. In this way, when MFC1, MFC2, and MFM3 are used to obtain the measured value of the flow rate of the raw material, when the ALD method is performed, the raw material gas system is intermittently supplied, and the supply time is short, so the measured flow rate will increase ( Rise) and fall before it becomes stable, so it may become unstable. Therefore, the measured values of MFC1, MFC2, and MFM3 are obtained by dividing the integrated value of the measured value of the flow rate for one cycle of ON and OFF of valve V1 by the time of one cycle, as described in detail later in this example. Use (evaluation) as the measured output value (indicated value).

In addition, in the memory 93, for example, the heating temperature of the raw material container 14, that is, the increase or decrease in the flow rate of the carrier gas at 160°C, and the gasification that flows into the raw material gas supply path 32 together with the carrier gas are memorized. Information about the relationship between the increase and decrease of the flow of raw materials, such as the relationship formula. This relational expression is approximated by a linear expression like the following equation (1), for example.

The increase or decrease of the flow rate of the gasified raw material = k (constant) × the increase or decrease of the flow rate of the carrier gas ‧ ‧ (1)

In the program stored in the program storage unit 92, a group of steps for executing the operation of the raw material gas supply unit 10 is written. In addition, the so-called program terms are used in the meaning of software that also includes process recipes and so on. The step group includes a step of integrating the measurement output of each flow rate of MFC1, MFC2, and MFM3 during the supply time period, and treating the integrated value as a flow rate value during the supply period and calculating the step. In addition, for the calculation processing of integration, a hardware configuration using a time constant circuit can also be used. Programs, such as being stored on hard disks, CDs, magneto-optical disks, memory cards, and other storage media, are installed on computers.

The action of the film forming apparatus according to the embodiment of the present invention will be explained using the flowchart shown in FIG. 3. Here, one lot is ordered to contain two or more wafers 100, for example, 25 wafers 100. First, after the power of the film forming apparatus is turned on, for example, a carrier containing wafers 100 of the first lot (the first lot after the power of the film forming apparatus is turned on) is carried into the carrier platform. In this case, go to step S4 through step S1 and step S2, and obtain the compensation value according to the conditions of the processing recipe of the first batch.

The compensation value is explained here. 4 illustrates the use of the raw material gas supply unit 10, the carrier gas supply source 11 and the diluent gas supply source 21 separately supply carrier gas and diluent gas, after passing through the MFM3, the film formation processing unit 40 when the gas is supplied from the MFM3 The measured value m3 is the value obtained by subtracting the total value of the measured value m1 of MFC1 and the measured value m2 of MFC2. From time t ₀ to t ₁₀₀ , it represents the value of (m3-(m1+m2)) when the carrier gas is supplied to the raw material gas supply path 32 through the bypass passage 7 without passing the raw material container 14 through. During the period from time t ₀ to t ₁₀₀ , the gas passing through the MFM 3 becomes a gas obtained by combining the carrier gas supplied from the carrier gas supply path 12 and the diluent gas supplied from the diluent gas supply path 22. However, the difference between the measured value m3 of MFM3 and the total value (m1+m2) of the measured value m1 of MFC1 and the measured value m2 of MFC2 does not become 0 as shown in FIG. 4 and an error occurs. The value of this error is equivalent to the compensation value. This error is caused by the individual error of each machine of MFM3, MFC1 and MFC2.

The following is an explanation of the project to obtain the compensation value. The operation of obtaining the compensation value is to set the set values of MFC1 and MFC2 to the flow value of the carrier gas and the flow value of the dilution gas determined in accordance with the target value of the flow rate of the raw material gas written in the processing recipe. In addition, it is set to perform the opening and closing of the valve V1 according to the same schedule as the opening and closing schedule of the valve V1 in the period during which the supply of the raw material gas supplied to the film formation processing section 40 in the processing recipe and the rest period are used to obtain the compensation value. The pressure of is set to the pressure determined by the processing formula, and the operation is performed.

The setting value of this MFC1, for example, when the solid raw material in the raw material container 14 is replenished to the maximum, is determined based on the flow rate of the carrier gas that can supply the raw material at the target value. The increase or decrease in the flow rate of the raw material is related to the carrier gas. The relationship between the increase and decrease of the flow rate is stored in the memory 93, for example. In addition, with the pressure adjusting section 94, the film forming processing section 40 The pressure is set to the set pressure in the processing recipe. In addition, it takes time to adjust the temperature of the film-forming processing section 40, and the vaporized raw material may adhere to a low-temperature portion and may be solidified. Therefore, the temperature of the film formation processing unit 40 is set in advance to 170° C., which is the temperature under the film formation processing, for example.

Regarding the setting of the flow rate of the diluent gas, the flow rate of the raw material is small. Therefore, for example, when the total flow rate of the raw material gas diluted by the diluent gas is determined as the total flow rate of the carrier gas and the diluent gas, it is determined to be from The total flow rate is the value obtained by subtracting the flow rate setting value of the carrier gas. In addition, when the flow rate of the raw materials is also included in the total flow rate, the target value of the supply amount of the raw materials is, for example, regarded as the weight per unit time, so it will be calculated based on the target value of the process pressure and the supply amount of the raw materials Take the total flow rate and the flow rate of the carrier gas used to supply the raw material. Therefore, the value obtained by subtracting the total value of the supply amount of the raw material and the flow rate of the carrier gas from the total flow rate becomes the set value of the flow rate of the diluent gas.

Then, the valves V3, V5, V6, and V7 are opened _{, and after time t 0} , the valve V1 is opened and closed at the same cycle as the opening and closing time point of the valve V1 in the processing recipe. Here, for example _{, during the period from time t 0} to time t ₁₀₀ , the operation of opening the valve V1 for one second and closing for one second is repeated 100 times. In addition, the inside of the vacuum container 41 has been evacuated. In this way, starting from the carrier gas supply source 11, the carrier gas system circulates in the order of the carrier gas supply path 12 and the bypass path 7 at a flow rate corresponding to the set value of the MFC1, and then flows through the source gas supply path 32 ( Bypass flow). After that, the source gas supply path 32 is mixed with the diluent gas supplied from the diluent gas supply path 22 and flows through the MFM 3, so that the mixed gas of the carrier gas and the diluent gas flows into the film formation processing section 40 intermittently.

Then obtain the measured value of the flow rate in each of MFC1, MFC2, and MFM3 under _{t 0} ~ t _100. Fig. 5(a) shows the state of the valve V1 for supplying and shutting off the source gas. The ON time zone corresponds to the supply period of the source gas, and the OFF time zone corresponds to the rest period of the source gas. Fig. 5(b) shows the transition of the measurement output (indicated value) of the flow rate of the raw material gas measured by MFM3 in the period _{from time t 0} to t _100. In this way, the time for opening the valve V1 is short, so the measurement output of the flow rate of the raw gas measured by MFM3 will rise sharply after the ON command of the valve V1, and drop immediately after the OFF command of the valve V1 . In addition, the ratio between the supply period and the rest period in Figure 5(a) is just drawn randomly.

Therefore, the measurement output of each flow rate of MFM3, MFC1, and MFC2 is obtained by integrating the control unit 9 during the period of one cycle during which the supply of each raw material gas is stopped, and dividing the integrated value by the time T of one cycle. The value is set as the measured value of the flow rate. Here, based on the ON command of the valve V1 shown in FIG. 5(a), for example, the integral action of the gas flow starts _{at time t 0} , and the integral action is ended at the _{time t 1 when the next ON command of the valve V1 is output.} Set this t ₀ to t ₁ as 1 cycle.

Then in each of MFC1, MFC2, and MFM3, _{the integral value obtained by integrating the flow from t 0} to t ₁ is divided by the time T of 1 cycle, that is, the time from time t ₀ to t ₁ (t ₁ -t ₀ ) (integrated value/(t ₁ -t ₀ )), respectively set as the measured value m1 of MFC1, the measured value m2 of MFC2, and the measured value m3 of MFM _{at time t 0} to t _1.

In this way, in _{each period from t 0} to t ₁ , t ₁ to t ₂ ..., the values of m1, m2, and m3 are calculated, and (m3-(m1 +m2)) value. Then, for example, the average value of (m3-(m1+m2)) values for 100 cycles _{from t 0 is set as the compensation value.}

Returning to FIG. 3, after obtaining the compensation value in step S4, when the compensation value is within the allowable range, the result is "YES" in step S5, and the process proceeds to step S6. Next, the wafer 100 is carried into the film formation processing section 40, the processing of the first wafer 100 is started, and the actual measured value m of the flow rate of the raw material is obtained. The compensation value is the error between MFM3 and MFC1 and MFC2, so when it is too large, it can be considered as an error caused by factors other than the measurement error of MFM3, MFC1 and MFC2. Therefore, pre-determining can be regarded as the allowable range of individual errors between MFM3 and MFC1 and MFC2.

In step S6, the heating unit 13 of the raw material container 14 is previously turned on, and the raw material container 14 is heated to, for example, 160° C. to sublime the solid raw material, and the concentration of the raw material in the raw material container 14 is increased to a concentration close to the saturation concentration. Then, the wafer 100 is carried into the film formation processing section 40, and the actual measurement value m of the flow rate of the raw material described later is obtained. That is, it is set to the flow value of the carrier gas and the flow value of the diluent gas written in the processing recipe, and the pressure of the film-forming processing section 40 is set to the pressure determined by the processing recipe. At time t _a , the valve V7 is closed And open the valves V2 and V4. In this way, the carrier gas is supplied from the carrier gas supply path 12 to the raw material container 14 at a flow rate set by the MFC1. In the raw material container 14, the vaporized raw material and the carrier gas flow to the raw gas supply path 32 together. . In addition, there is a confluence of the dilution gas flowing from the dilution gas supply path 22 into the source gas supply path 32. Then, starting from time t _a , the valve V1 is opened and closed in the cycle of the opening and closing of the valve V1 in the processing recipe. Here, the valve V1 is repeatedly opened for one second and closed for one second. In this way, the raw material gas mixed with the diluent gas is sent to the film formation processing section 40 (automatic flow). Therefore, the flow value of the carrier gas and the flow value of the diluent gas, the pressure of the film formation processing unit 40, and the cycle of opening and closing the valve V1 are set to the same setting values as the process for obtaining the compensation value, and the carrier gas is supplied to The raw material container 14 supplies the raw material gas to the film formation processing unit 40.

As a result, as shown in Figure 5(c), the raw material gas rises rapidly after the ON command of the valve V1, and rises to a value greater than the measured value _{from time t 0} to t _{100, and} The pattern that drops immediately after the OFF command of the valve V1.

Then, in the processing of the first wafer 100, as from time t ₀ to t ₁₀₀ , in each of MFC1, MFC2, and MFM3, it is calculated to integrate the flow rate _{from t a} to t _a+1. The integral value divided by the time T of 1 cycle, which is the time from time t _a to t _a+1 (t _a+1 -t _a ), is the value (integral value/(t _a+1 -t _a ) ), and set as the measured value m1 of MFC1, the measured value m2 of MFC2, and the measured value m3 of MFM _{at time t a} to t _{a+1, respectively.} Also, for each cycle of the gas supply cycle, subtract the sum of the measured value m1 of MFC1 and the measured value m2 of MFC2 from the measured value m3 of MFM3, and obtain the value of (m3-(m1+m2)) for each cycle value. The value of (m3-(m1+m2)) in each period after time ta, as shown in FIG. 4, should be subtracted from the total flow rate of the raw material gas diluted by the dilution gas and supplied to the film formation processing section 40 The value obtained by the sum of the flow rate of the carrier gas and the flow rate of the dilution gas, that is, the flow rate of the raw material.

However, as described above, the measurement value of MFM3 and the total value of the measurement value m1 of MFC1 and the measurement value m2 of MFC2 may include errors caused by the difference between MFM3 and the measurement output of the MFC1 and MFC2 devices. The value equivalent to this error is the above-mentioned compensation value. Therefore, by calculating (m3-(m1+m2) for each period of the raw material gas supply after the _{time t a shown in Fig. 4 and Fig. 5(c)} ), and subtracting _{the compensation value from time t 0} to t ₁₀₀ , the actual measured value m of the flow rate of the raw material supplied to the film forming processing section 40 is obtained. The actual measured value m is converted into the value of the raw material (mg/min) by the following formula (2).

Raw material (mg/min) = flow rate of raw material (sccm) × 0.2 (Conversion Factor)/22400 × molecular weight of raw material (WCl ₆ : 396.6) × 1000‧‧‧(2)

Then in step S7, set N=2, and proceed to step S8. Then, in step S8, when the actual measured value m of the flow rate of the raw material falls within the set range, it becomes "YES", and the process proceeds to step S9. In step S9, the second (N=2) wafer 100 is processed like the first wafer 100, and the actual measured value m of the flow rate of the raw material is obtained.

On the other hand, in step S8, when the N-1th wafer, in this case, the first wafer 100, the actual measured value m of the flow rate of the raw material is out of the control range (set range), it becomes "NO", Proceed to step S21. Next, when the actual measured value m of the flow rate of the raw material is not a value judged to be an error (abnormal value), the process proceeds to step S22.

Next, in step S22, the flow rate of the carrier gas is adjusted, and the flow rate of the raw material is adjusted. As mentioned above, the increase and decrease a1 of the flow rate of the carrier gas and the increase and decrease Δm of the flow rate of the raw material that circulates with the carrier gas, as shown in Fig. 7, if the increase and decrease y of the flow rate of the raw material and the flow rate of the carrier gas are The increase or decrease amount x will be approximated by the linear formula y=k(x) with the slope k. On the other hand, with respect to the current measured value m1 of MFC1, the flow of the raw material is the actual measured value m of the flow rate of the raw material. The difference between the actual measured value m of the flow rate of the raw material and the target value of the flow rate of the raw material can be defined as the increase/decrease amount Δm of the raw material. Therefore, Δm=k×a1, and a1 can be obtained. Then add this a1 to the current measured value of MFC1. MFC1 is adjusted so that the flow rate of the set value becomes the measured value, so by adding a1 to the current set value of MFC1, the measured value of MFC1 can be (m1+a1). In addition, by adding a1 to the measured value of MFC1, the total flow rate of the source gas diluted by the dilution gas supplied to the film formation processing unit 40 increases, and the pressure fluctuates. Therefore, the value obtained by subtracting a1 from the current setting value of MFC2 is changed so that the value obtained by subtracting a1 from the current measurement value m2 of MFC2 (m2-a1) becomes the measured value. Then, it progresses to step S9, the process of the N-th wafer 100 is performed, and the actual measured value m of the flow rate of a raw material is acquired.

Next, proceed to step S10, the second wafer 100 is not the final wafer 100, so it becomes "NO". In step S11, set N=3 and return to step S8. Then in step S8, it is determined whether the actual measured value m of the flow rate of the raw material under the film formation process of the N-1th wafer 100, which is the second wafer 100, is within the set range, when the flow rate of the raw material When the actual measurement value m falls within the setting range, go to step S9 and use the second The set value of the flow rate of the carrier gas under the processing of the wafer 100 of the sheet is processed for the wafer 100 of the third sheet, and the actual measured value m of the flow rate of the raw material is obtained. When the actual measured value m of the flow rate of the raw material of the second wafer 100 does not fall within the set range, the flow rate of the carrier gas is adjusted in steps S21 and S22, and the third wafer 100 is processed . The process from step S8 to step S11 is repeated in this way, and sequential processing is performed on all wafers 100 in the lot.

FIG. 8 shows an example of the actual measured value m of the flow rate of the raw material of each wafer 100 as described above. For example, in step S9, when the value of the actual measured value m of the flow rate of the raw material during the film formation process of the fourth wafer 100 is out of the set range, proceed to step S11 via step S10, and rewrite n to 5 After that, it proceeds to step S8. The actual measured value m of the flow rate of the raw material during the film formation process of the fourth wafer 100 is a value outside the set range, so the process proceeds to step S21. Next, as shown in FIG. 8, when the actual measured value m of the flow rate of the raw material is not a value judged to be an error (abnormal value), the process proceeds to step S22, the flow rate of the carrier gas is adjusted, and the flow rate of the raw material is adjusted.

The processing of each wafer 100 is performed in this way, and the final wafer 100, which is the 25th wafer 100 here, becomes "YES" in step S10 and ends.

Next, explain it for subsequent batches. Once the subsequent batches are transferred to the carrier platform, step S1 proceeds to step S2. The current lot is not the first lot, so it becomes "NO" in step S2, and the process proceeds to step S3. Then in step S3, it is determined whether the processing recipe for the wafer 100 of the current lot is different from the processing recipe of the previous lot (previous lot). Specific and In other words, for example, it is determined whether the three items of the flow rate of the raw material in the processing recipe (the target value of the flow rate of the raw material), the set pressure of the film formation processing unit 40, the supply of the raw material gas under the film formation process, and the rest period are the same. When at least one item is different, it becomes "YES", and the process proceeds to step S4. Then, in step S4, based on the processing recipe for the wafer 100 of the current lot (subsequent lot), the target value of the flow rate of the raw material, the set pressure of the film formation processing unit 40 and the supply of the raw material gas under the film formation process are set, The cycle of rest. Then, the compensation value is obtained as in the previous batch, and the process proceeds to step S5. When the compensation value falls within the allowable range, the process proceeds to step S6, and then the process after step S6 is performed.

In addition, when the processing recipe of the subsequent batch and the processing recipe of the previous batch (previous batch), specifically, for example, the flow rate of the raw material in the processing recipe (the target value of the flow rate of the raw material), the set pressure of the film forming processing unit 40 If the three items of the supply of raw material gas and the period of halt during the film forming process are the same, it becomes "NO" in step S3 and proceeds to step S6 to use the compensation value used in the previous batch, and then proceeds to step S6 Future projects.

In addition, if the compensation value is obtained in accordance with the batch processing recipe, if the compensation value is out of the allowable range, it becomes "NO" in step S5, and the process proceeds to step S30 to sound an alarm and terminates. In this case, there may be errors caused by factors other than the individual errors of MFM3, MFC1 and MFC2, so repairs are required.

In addition, in step S8, when the actual measured value m of the flow rate of the raw material of the n-th wafer 100 is out of the set range, it is judged to be wrong. In the case of an incorrect value (abnormal value), the process proceeds from step S8 to step S21, and it becomes "YES" in step S21. Therefore, the process proceeds to step S30, the alarm is sounded, and the end is completed. For example, maintenance of the raw material gas supply unit 10 is performed.

In the above embodiment, the carrier gas is supplied to the raw material container 14, the gasified raw material and the carrier gas flow out from the raw material container 14, and then diluted with the diluent gas and supplied to the film formation processing unit 40. The difference between the actual measured value and the target value of the flow rate of the raw material is used to adjust the flow rate of the carrier gas. Then, the difference value obtained by subtracting the sum of the measured values of the respective flow rates of the carrier gas and the dilution gas from the measured value of the total of the respective flow rates of the raw material, carrier gas, and dilution gas obtained by gasification, and subtracting Measure the error between the individual of the machine as the compensation value, and treat it as the actual measured value of the flow rate of the raw material. Therefore, the individual error of each measuring machine will be offset, and the correct actual measurement value of the amount of raw material can be obtained, and the supply amount of carrier gas can be adjusted based on the actual measurement value. Therefore, the supply amount of raw material per wafer 100 will be reduced. stable.

In addition, when the ALD method is implemented, the integrated value of the measurement output during one cycle of the supply of raw gas and the stop of each measurement device is regarded as the flow measurement value. Therefore, it is possible to avoid the increase in the gas flow rate in a short time. The instability of the measurement caused by falling. Therefore, the measured value of the gas flow rate can be obtained stably, and as a result, the supply amount of the raw material gas per wafer 100 can be stabilized.

In addition, in the measurement of the actual measurement value of the flow rate of the raw material shown in step S6 to step S10, it is also possible to design the measurement of the actual measurement value m of the flow rate of the raw material before the processing of the batch of wafers 100. For example, it can also be designed After setting the same setting conditions as the processing recipe of the batch, do not load the wafer 100 into the vacuum vessel 41 but perform a dummy process of hypothetical supply of the raw material gas, thereby performing the measurement of the actual measured value m of the flow rate of the raw material . In this way, the accuracy of the flow rate of the raw material gas under the processing of the first wafer 100 can be improved.

In addition, for example, in the film forming apparatus, before the batch processing or after the cleaning process in the vacuum vessel 41, precoating is performed, that is, the film forming gas is supplied to the vacuum vessel 41 so that it is deposited to the inner surface to rectify the vacuum. The condition of the container 41 is a condition, but it can also be designed to measure the actual measurement value m of the flow rate of the raw material in this pre-coating process.

In addition, when the measured values m1, m2, and m3 of the flow rate are calculated, the control unit 9 can also measure and output the respective flow rates of MFM3, MFC1, and MFC2 for n (2 or more) of the period of the supply and stop of each raw material gas. The period of the cycle is integrated, and the value obtained by dividing the integrated value by the time nT of n cycles is set as the measured values m1, m2, and m3 of the flow rate.

In addition, in order to prepare the pre-coating conditions, it is preferable that the accuracy of the flow rate of the raw material gas supplied to the vacuum container 41 be high. Therefore, it can also be designed to perform a dummy process before the pre-coating process to measure the actual measured value m of the flow rate of the raw material to improve the accuracy of the flow rate of the raw material gas in the pre-coating process. For example, a fake process is performed like step S6 in FIG. 3, whereby the actual measured value m of the flow rate of the raw material is obtained. Then it is judged whether the actual measured value m of the flow rate of the raw material is within the set range (step S8). When the actual measured value m of the flow rate of the raw material is not within the set range, the flow rate of the carrier gas may be adjusted and the pre-coating treatment may be performed.

In addition, it can also be designed to obtain the actual measured value m of the flow rate of the raw material by, for example, the supply of raw material and the integrated value of one cycle of rest, and the raw material supply amount can be adjusted in real time during the film formation process of one wafer 100 . For example, the PID calculation process is performed by the difference between the actual measured value m of the flow rate of the raw material and the target value of the flow rate of the raw material acquired in the period T1 during which the supply of the raw material is stopped at a certain time, and the deviation amount is extracted. Then, based on the deviation amount, the subsequent supply of the raw material in the period T1 or the supply amount of the raw material in the halted period may be adjusted.

The present invention can also be applied to a film forming apparatus that performs a film forming process by the CVD method. In the CVD method, the source gas is continuously supplied to the film formation processing section 40, and the reaction gas is continuously supplied to form a film on the wafer 100. In the CVD method, the flow rate measurement output of MFM3, MFC1, and MFC2 when the flow rate of the raw material gas is stable can also be set as the measured values m1, m2, and m3 of MFM3, MFC1, and MFC2, respectively.

In addition, in the CVD method, during the supply period of the raw material under the processing of one wafer 100, for example, the actual measured value m of the flow rate of the raw material can be measured at 0.1 second intervals, and the actual measured value m of the flow rate of the raw material at a certain moment If it deviates from the setting range, immediately adjust so that the actual measured value m of the flow rate of the raw material is within the setting range.

By adjusting the flow rate of the raw material in real time in this way, it is not necessary to obtain the actual measured value m of the flow rate of the raw material with the first wafer 100 and dummy processing.

Furthermore, the raw materials contained in the raw material container 14 are not limited to solid raw materials, and may be liquid raw materials.

In addition, in step S22, when adjusting the flow rate of the carrier gas, a function corresponding to the flow rate value of the carrier gas and the flow rate value of the raw material can also be used, such as a linear formula, and the actual measured value and target value of the flow rate value of the raw material are obtained from the aforementioned function. The values correspond to the flow value of the carrier gas respectively, and the flow rate of the carrier gas is adjusted according to the difference between the two carrier gas flow values.

In addition, in the present invention, a tank for temporarily storing the raw material gas may be provided on the downstream side of the MFM3 and on the upstream side of the valve V1. In this case, the raw material gas stored in the tank can be supplied to the film formation processing section 40 at one go, and the flow rate of the raw material supplied to the film formation processing section per unit time can be increased. Therefore, the time for opening the valve V1 can be shortened, and there is an advantage that the processing time of the wafer 100 can be shortened.

In addition, for example, when the wafer 100 is processed by the ALD method, in order to continuously form a plurality of films with different film qualities, the flow rate of the raw material and the supply time of the raw material gas may be performed (the amount of the raw material gas in one cycle). A plurality of ALDs of which at least one of the supply time is different from each other. As an example, it is assumed that the film formation process performed on the wafer 100 is composed of a first ALD and a second ALD following it, and the flow rate of the raw material and the supply time of the raw gas are different between the first ALD and the second ALD. For example, imagine a film formation process that requires 100 cycles of feed/cutting of the raw material, the flow rate of the raw material and the supply time of the raw material gas in the 50 cycles of the first ALD, and the flow rate of the raw material and the raw material in the 50 cycles of the second ALD The gas supply time may use different processing recipes. In this case, in the process of obtaining the compensation value in step S4 shown in FIG. 3, the compensation value under the first ALD and the compensation value under the second ALD are obtained.

Then in step S6 shown in FIG. 3, when the actual measured value m of the flow rate of the raw material supplied from the raw material container 14 is obtained, the compensation value of the first ALD will be used to obtain the flow rate of the raw material in the film formation process performed by the first ALD. The measured value m. Then, in the film formation process performed by the second ALD, the compensation value of the second ALD is used to obtain the actual measured value m of the flow rate of the raw material.

Then it is designed to perform step S8, step S21, and step S22 in FIG. 3 for each m.

In addition, in step S4 shown in FIG. 3, when the compensation value is obtained, a formula prepared with calculation parameters that are selected from the processing formula and the process parameters that have a large impact on the compensation value can also be used.

For example, as shown in FIG. 9, the memory 93 of the control unit 9 is provided with an area for storing a calculation formula 93a, and a calculation formula format 93b used as a format for creating the calculation formula 93a is stored. In addition, the program storage unit 92 stores a processing program 92a for executing the operation of the raw material gas supply unit 10 shown in the flowchart shown in FIG. 3, and also stores a recipe preparation program 92b for preparing the calculation formula 93a.

Next, the formula 93b for calculation will be described, but first, the processing formula will be described. The processing recipe is a matter that specifies the procedures for each batch and the process related to the wafer 100 of the lot. FIG. 10 is an example of the actual processing recipe in a simplified way. The processing recipe shown in Figure 10 includes the "step number" indicating the execution sequence, the "execution time" of each step, "ON/OFF of valve V1", and the "repetitive target step" indicating the step number to be executed after the step is completed "And "Repetitions", indicating the "flow mode" of switching between bypass flow and automatic flow caused by the operation of valves V2, V4 and V7, indicating the carrier gas flow rate (sccm) of "Carrier N ₂ ", indicating the dilution gas _{The "compensation N 2} "of the flow rate (sccm), and the "pressure" (Torr) of the film formation processing unit 40. The “bypass flow” is a supply method in which the carrier gas is supplied to the raw material gas supply path 32 via the bypass passage 7 while avoiding the raw material container 14, and the mixed gas of the carrier gas and the diluent gas is supplied to the film formation processing unit 40. In addition, the so-called "automatic flow" is a supply method of supplying carrier gas to the raw material container 14, supplying carrier gas containing the vaporized raw material to the raw material gas supply path 32, and supplying the raw material gas to the film formation processing section 40 . In addition, the processing recipe shown in FIG. 10 reveals the part of the recipe related to the supply of the raw material gas in the processing recipe of the film forming process of the wafer 100, and the part related to the supply/cutting of the reactive gas and the replacement gas is omitted.

If the operation is described according to the processing recipe shown in FIG. 10, after the wafer 100 is loaded into the vacuum container 41, it stands by for 50 seconds, and in step 2, the pressure of the film forming processing unit 40 is adjusted to 80 Torr. Next, set the carrier flow rate to 300 sccm and the diluent gas flow rate to 1100 sccm, and repeat 40 times the operation of opening the valve V1 for 0.4 seconds and closing for 0.3 seconds. Next, after adjusting the pressure of the film formation processing unit 40 to 40 Torr, the carrier flow rate is set to 700 sccm and the diluent gas flow rate is set to 600 sccm, and the operation of opening the valve V1 for 0.4 seconds and closing for 0.3 seconds is repeated 30 times. After that, the supply of raw materials to the film formation processing section 40 is stopped, and the inside of the vacuum vessel 41 is evacuated to a predetermined vacuum pressure. Therefore, the processing recipes are two ALD processing recipes for performing the first ALD shown in steps 3 and 4 and the second ALD shown in steps 6 and 7 on the wafer 100.

Next, the formula 93b for calculation will be explained. As shown in Figure 11, the formula 93b for calculation includes "step number", "execution time", "ON/OFF of valve V1", and "repeated target step" like a processing formula. "Number of iterations", "Flow mode", "Carrier N ₂ "indicating the carrier gas flow rate (sccm), "Compensation N ₂ " indicating the diluent gas flow rate (sccm), "Pressure" (Torr) of the film formation processing unit 40 . In the formula format 93b for calculation, the part that affects the acquisition of the compensation value is blank, and the parameters that do not affect the acquisition of the compensation value are shared with the processing recipe. For example, the formula format 93b for calculation is composed of the "execution time" in steps 3 and 4 and steps 6 and 7, the "carrier N ₂ "and "compensation N ₂ " in steps 3-7, and the "compensation N 2" in steps 2-8. The item of "pressure" is left blank so that it can be written for each processing recipe. In addition, the "flow mode" in steps 1-9 is bypass flow, and the number of repetitions of steps 4 and 7 is 10 times.

The calculation formula 92a does not require the actual supply of raw materials, so the flow mode and the processing recipe are different, and the number of repetitions of the valve V1 switch and the processing recipe are different. In the processing recipe, the film forming process is performed to switch the valve V1, for example, 100 times repeatedly, but the difference in the number of repetitions of the valve V1 switch does not affect the compensation value. Therefore, it is designed to reduce the number of repetitions of the opening and closing of the valve V1 to shorten the time for obtaining the compensation value. In addition, although it is not included in the recipes of FIGS. 10 to 12, for example, a small amount of raw material gas remaining in the raw material gas supply path 32 may be supplied to the film formation processing section 40, so the supply of reactive gas is not performed.

The description is given for the recipe preparation program 92b. Once the step S4 shown in FIG. 3 is entered, first, the processing recipe corresponding to the current batch shown in FIG. 10 will be sent from the host computer 99 to the memory 93 of the control unit. Then the formula creation program 92b reads and calculates the items corresponding to the blank part of the formula format 93b from the processing formula, that is, the "carrier N ₂ "and "compensation N ₂ " in steps 3~7, and in steps 2~8 The value of the "pressure" of the film formation processing unit 40, the "execution time" of steps 3 and 4, and steps 6 and 7. In addition, each of the read values is written into the corresponding blank of the calculation recipe format 93b shown in FIG. 11. In this way, the calculation formula 93a shown in FIG. 12 is created and stored in the memory 93.

Then, the compensation value is obtained using the formula 93a for calculation created by the formula 92b. As shown in the verification test described later, the compensation value is affected by the flow rate of the carrier gas and the diluent gas, and is also affected by the temperature of the film formation processing unit 40. In addition, the compensation value is affected by the pressure of the film formation processing unit 40 or the cycle of opening and closing the valve V1 even if the flow rate of the carrier gas is the same. In addition, when the compensation value is acquired, the temperature of the film formation processing unit 40 is already set to the temperature of the film formation processing, so the temperature is not considered.

Therefore, for each processing recipe, the opening and closing time of the valve V1 in which the processing recipe is written, the flow rate of the carrier gas and the diluent gas, and the calculation recipe 92a of the set pressure of the film formation processing section 40 are set, thereby The correct compensation value can be obtained for each processing formula. Therefore, the accuracy of the actual measured value of the flow rate of the raw material obtained by subtracting the compensation value from the measured value of the flow rate of the raw material becomes higher. In addition, the calculation formula 92a is used as described above, so the burden of data processing is small.

In addition, when the wafer 100 of each batch is continuously processed for film formation with the same processing recipe, the remaining amount of the raw material in the raw material container 14 will decrease as the wafer 100 is processed. In steps S21 and S22 shown in FIG. 3, when the flow rates of the carrier gas and the dilution gas are adjusted, the temperature of the raw material gas will change due to the temperature difference between the carrier gas and the dilution gas, etc., and the compensation value may gradually deviate. Therefore, it may be designed to change the compensation value, for example, when the number of processed wafers 100 reaches a certain number of wafers, or when the supply time of the raw material gas reaches a certain time. For example, after the processing batch ends, in the subsequent batch processing, the following steps can also be set after step S2 in FIG. 3, that is, when the number of wafers 100 processed reaches a certain number of wafers, it becomes It goes to step S4 with "Yes", and it becomes "No" when the number of processed wafers 100 has not reached a certain number, and goes to step S3. With such a configuration, when the same processing recipe is used continuously, even if the number of processed chips increases or the processing time becomes longer, the compensation value will be corrected if the error of each device of MFM3, MFC1, and MFC2 increases. , And it is possible to accurately obtain the actual measured value m of the flow rate of the raw material. In addition, in the batch processing, it can also be designed to temporarily interrupt the batch processing to obtain the compensation value.

In addition, for example, when the influence of the compensation value on the pressure of the film formation processing unit 40 is small, the gas may be evacuated from the source gas supply path 32 through the avoidance path of the film formation processing unit 40 to obtain the compensation value.

[Verification test]

In order to investigate the relationship between the processing formula and the compensation value, the following experiments were carried out. Using the film forming apparatus shown in the embodiment of the present invention, using the film forming processing section The pressure and temperature of 40, the supply and rest period of the raw gas, and the different flow rates of carrier gas and diluent gas are treated with different compensation values.

FIG. 13 is a schematic characteristic diagram of the relationship between the flow rate of the carrier gas and the compensation value in an example in which the compensation value is obtained using a processing recipe in which the flow rate of the dilution gas is set to 0. In addition, FIG. 14 is a characteristic diagram showing the relationship between the total flow rate of the carrier gas flow rate and the diluent gas flow rate and the compensation value in an example in which the compensation value is obtained using the treatment recipe for supplying carrier gas and diluent gas. In FIGS. 13 and 14, the diagrams are changed according to the temperature of the film formation processing section 40.

According to this result, as shown in Figs. 13 and 14, it can be seen that the compensation value tends to increase by increasing the flow rates of the carrier gas and the diluent gas. However, it can be seen that even when the flow rates of the carrier gas and the diluent gas are set to be constant, the compensation value will be inconsistent depending on the temperature or pressure of the film formation processing section 40, the opening and closing cycle of the valve V1, and other processing recipe settings. . Therefore, when the processing parameter is changed as described above, it is advantageous to use the processing parameter to obtain the compensation value.

Claims (11)

A raw material gas supply device that vaporizes solid or liquid raw materials in a raw material container and serves as raw material gas together with carrier gas through a raw material gas supply path to supply raw material gas to a film forming processing section that processes a substrate into a film The device is characterized by comprising: a carrier gas supply path for supplying carrier gas to the raw material container; a bypass passage that branches from the carrier gas supply path to avoid the raw material container and is connected to the raw gas supply path; and a dilution gas supply The path is connected to the downstream side of the raw gas supply path than the connection part of the bypass passage, and is used to make the dilution gas flow to the raw gas; the first mass flow controller and the second mass flow controller are respectively connected to the aforementioned A position in the carrier gas supply path upstream of the branch of the bypass passage and the dilution gas supply path; a mass flow meter provided on the downstream side of the confluence of the dilution gas supply path in the raw gas supply path; a switching mechanism, Switch the carrier gas path from the carrier gas supply path to the raw gas supply path between the inside of the raw material container and the bypass path; the control unit connects the first mass flow controller, the second mass flow controller, and the mass flow meter The measured values of the flow rate are set as m1, m2, and m3, respectively, and execute: the first step is to process the first substrate of the batch of substrates Previously, read the target value of the flow rate of the raw material from the processing recipe of the batch, set the set value of the first mass flow controller to the carrier gas flow rate corresponding to the target value of the flow rate of the raw material, and switch the carrier gas path. In the state of the bypass passage, the carrier gas and the dilution gas are circulated to obtain the calculated value of {m3-(m1+m2)}, that is, the compensation value; and the second step is to switch the carrier gas passage to the raw material container Calculate the calculated value of {m3-(m1+m2)} by circulating the carrier gas and the dilution gas in the state on the side, and subtract the aforementioned compensation value from this calculated value to obtain the actual measured value of the flow rate of the raw material, and obtain the actual value of the raw material flow rate. The difference between the target value of the flow rate and the aforementioned actual measured value; and the third step is to adjust the setting value of the first mass flow controller based on the aforementioned difference value and the relationship between the increase or decrease of the flow rate of the raw material and the increase or decrease of the carrier gas so that The flow rate of the raw material becomes the target value, and the setting value of the second mass flow controller is adjusted so that the total flow rate of the raw material gas and the dilution gas becomes the setting value. The raw material gas supply device described in claim 1, wherein the film forming process performed in the aforementioned film forming processing section is to alternately supply a raw material gas and a reaction gas that can react with the raw material gas to the substrate. The film forming process performed by supplying the replacement gas between the supply and the supply of the reaction gas, the measured values m1, m2, and m3 in the second step above, if the supply and stop period of the raw gas is set as T, then it is The value obtained by dividing the integral value of the flow rate under the period of n (n is an integer greater than 1) by the time nT of the period of n. The raw material gas supply device described in the scope of the patent application, wherein the aforementioned control unit processes the first substrate of the batch of substrates, Read the period T of the supply and stoppage of the raw gas from the processing recipe of the batch. The measured values m1, m2, and m3 in the first step are calculated by dividing the integrated value of the flow rate under n cycles by the time nT of the n cycles Got the value. The raw material gas supply device described in item 2 or 3 of the scope of patent application, wherein the control unit, before the first step, executes: read the setting of the first mass flow controller from the processing recipe of the substrate batch Value, and the setting value of the second mass flow controller, the pressure of the film formation processing unit, the gas supply to the film formation processing unit, and the steps of the period of rest; and write the parameters read above Enter the recipe format to create a calculation recipe. The recipe format specifies the flow of carrier gas and diluent gas while switching the carrier gas path to the bypass path, and the gas for the film formation processing section The number of times of switching between the supply and the stop; the first step described above, the compensation value is obtained by circulating the carrier gas and the diluent gas in accordance with the aforementioned calculation formula. The raw material gas supply device described in any one of items 1 to 3 in the scope of the patent application, wherein the difference value used in the third step is for the substrate to be subsequently subjected to film formation processing in the same batch The difference between the actual measured value of the flow rate of the raw material during the processing of the first substrate and the target value of the raw material. The raw material gas supply device described in any one of items 1 to 3 in the scope of the patent application, wherein the difference value used in the third step is the value of the false processing performed before the processing of the first substrate of the lot The difference between the actual measured value of the flow rate of the raw material and the target value of the raw material. A method for supplying raw material gas to vaporize the solid or liquid raw material in the raw material container, and supply the raw material gas together with the carrier gas as the raw material gas through the raw material gas supply path to the film forming processing section for processing the substrate into a film The method is characterized in that it is equipped with: a carrier gas supply path for supplying carrier gas to the raw material container; and a bypass passage, branched from the carrier gas supply path, avoiding the raw material container and connected to the raw gas supply path; And a dilution gas supply path connected to the downstream side of the raw gas supply path than the connection part of the bypass passage, for converging the dilution gas to the raw gas; and a first mass flow controller and a second mass flow controller , Respectively connected to the position of the carrier gas supply path upstream of the branch of the bypass passage and the dilution gas supply path; and a mass flow meter installed at the confluence of the dilution gas supply path in the raw gas supply path Downstream side; and a switching mechanism for switching the carrier gas passage from the carrier gas supply path to the raw gas supply path between the raw material container and the bypass path; the raw gas supply device includes: controlling the first mass flow rate The measured values of the flow rate of the device, the second mass flow controller, and the mass flow meter are respectively set as m1, m2, and m3, and the flow rate of the raw material is read from the processing recipe of the batch before the first substrate of the substrate batch is processed The set value of the first mass flow controller is set to the carrier gas flow rate corresponding to the target value of the flow rate of the raw material, and the carrier gas and the carrier gas are circulated while the carrier gas passage is switched to the bypass passage side. Dilute the gas to obtain the calculation value of {m3-(m1+m2)} that is the compensation value; With the carrier gas passage switched to the raw material container side, the carrier gas and diluent gas are circulated to obtain the calculation value of {m3-(m1+m2)}, and the compensation value is subtracted from the calculation value to obtain the raw material The process of obtaining the difference between the target value of the flow rate of the raw material and the actual measured value based on the actual measured value of the flow rate; adjust the first mass flow rate based on the foregoing difference value and the relationship between the increase or decrease in the flow rate of the raw material and the increase or decrease in the carrier gas The setting value of the controller makes the flow rate of the raw material a target value, and the setting value of the second mass flow controller is adjusted so that the total flow rate of the raw material gas and the dilution gas becomes the set value. The method for supplying raw material gas as described in item 7 of the scope of the patent application, wherein the film forming process performed in the above-mentioned film forming processing section is to alternately supply the raw material gas and the reactive gas that can react with the raw material gas to the substrate. Between the supply of the supply and the supply of the reaction gas, the replacement gas is supplied to perform the film formation process. With the carrier gas passage switched to the raw material container side, the carrier gas and the diluent gas are circulated to obtain {m3-(m1+ m2)} is the calculation value of the measured values m1, m2, and m3 in the process. If the period of supply and stop of the raw gas is set as T, then it is the integral of the flow rate under the period of n (n is an integer greater than 1) The value is divided by the time nT of n cycles. The raw material gas supply method described in the eighth patent application, in which the carrier gas and the diluent gas are circulated in a state where the carrier gas passage is switched to the bypass passage side to obtain {m3-(m1+m2) } The calculated value of the compensation value is the measured value m1, m2 and m3 in the engineering of the compensation value, which is the value obtained by dividing the integral value of the flow under n cycles by the time nT of the n cycles. The raw material gas supply method as described in item 8 or 9 of the scope of patent application, wherein, before the process of obtaining the aforementioned compensation value, it includes: reading the set value of the first mass flow controller from the processing recipe of the substrate batch , And the setting value of the second mass flow controller, the pressure of the film formation processing section, and the process of the gas supply to the film formation processing section and the parameters of the rest period; and write the above-mentioned read parameters into To the recipe format, the process of creating a recipe for calculation. The recipe format stipulates that the carrier gas and diluent gas flow in the state where the carrier gas passage is switched to the bypass passage side, and the gas in the film formation processing section The number of times of switching between supply and stop; the process of obtaining the aforementioned compensation value is to obtain the compensation value by following the aforementioned calculation formula, circulating carrier gas and diluent gas. A memory medium is a memory medium with a computer program stored in it. The computer program is used to vaporize the solid or liquid raw material in the raw material container, and the carrier gas is used as the raw material gas to be supplied to the substrate through the raw material gas supply path. The raw material gas supply device of the film forming processing section of the film forming process, the memory medium is characterized in that the aforementioned computer program is programmed with a group of steps to execute the raw material gas described in any one of the 7th to 10th patent applications Supply method.

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