JP3982670B2 - Operation control method and apparatus for plasma reactor system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an operation control method and apparatus for a plasma reactor system suitable for manufacturing liquid crystal devices and semiconductor devices.
[0002]
[Prior art]
A reaction furnace in which an object to be processed such as a liquid crystal device or a semiconductor device is charged, a plasma generation unit for generating plasma by exciting the gas in the reaction furnace, and a gas supply for supplying gas into the reaction furnace Conventionally, a plasma reactor system having a gas exhaust section for exhausting gas from a reactor and a gas exhaust section for exhausting gas from the reactor is known.
[0003]
In the manufacturing process of a semiconductor device or a liquid crystal display device using this kind of plasma reactor system, a certain amount of time is required until the concentration and pressure of the gas in the reactor are stabilized at both the start and end of the plasma reaction process. Wait time is needed.
[0004]
That is, when starting the plasma reaction process, the process gas is started by switching from the inert gas to the process gas, and then the gas concentration and pressure in the process chamber (reactor) are set to the target values. Until the plasma power is turned on, the process cannot be started. If the plasma power supply is turned on without waiting for the gas concentration and pressure to settle, the process time can be shortened, but the instability of the gas concentration and pressure causes a decrease in product accuracy and quality.
[0005]
Similarly, when the plasma reaction process is terminated, the gas concentration and pressure in the process chamber (reactor) are not affected even if the plasma power supply is shut off, the process gas is switched to an inert gas and the process gas supply is stopped. The process for the next process (for example, the process of opening the door of the process chamber and taking out the semiconductor substrate as the processing object) cannot be performed until the value is settled.
[0006]
[Problems to be solved by the invention]
Conventionally, a temperature distribution type is used as a flow rate regulator for each gas type of the gas supply unit in this type of plasma reactor system. The temperature distribution type flow regulator is configured to monitor the temperature proportional to the mass flow rate upstream and downstream of the regulator by a flow sensor, and to control the fluid by the temperature distribution at that time. When no fluid is supplied, the upstream and downstream temperature distributions do not occur, so the flow rate adjustment valve is fully open. For this reason, the flow rate becomes excessive immediately after the fluid supply, and a large pressure fluctuation occurs in both the total pressure and the gas partial pressure in the reactor, and it takes time to settle them.
[0007]
The conventional gas supply and plasma power-on timing are shown in the graph of FIG. The process shown in this example is SiH _Four , O ₂ , B ₂ H ₆ The plasma reaction treatment is performed on the surface of the liquid crystal device or the semiconductor device using the three types of gases. When the supply of three types of gases starts at time 0 when the inert gas flows, the total pressure and partial pressure of all the gases suddenly increase and then turn to a relatively gradual decrease, about 20 seconds after the start of supply. After a while, it can be seen that the set pressure is set.
[0008]
As can be seen from this, after switching the inert gas to the mixed gas of the inert gas and the process gas and supplying the process gas, the plasma power supply is turned on until the concentration and pressure of the gas in the process chamber are stabilized. If it is necessary to wait, a large extra waiting time is required in addition to the actual plasma reaction processing time, and the productivity decreases due to the lengthening of the TAT (Turn-Around Time) of the process.
[0009]
In addition, since the process gas continues to flow during the above-described waiting time, the utilization efficiency of the process gas is reduced and the manufacturing cost is increased.
[0010]
The present invention has been made paying attention to the above-mentioned problems, and its object is to realize a plasma reaction treatment process necessary for production of liquid crystal devices and semiconductor devices with high productivity and low cost. It is an object of the present invention to provide a method and apparatus for controlling the operation of a plasma reactor system that can perform the above-described operation.
[0011]
Other objects and operational effects of the present invention will be easily understood by those skilled in the art by referring to the description of the following specification.
[0012]
[Means for Solving the Problems]
The operation control method of the plasma reactor system of the present invention includes a reactor in which a processing object such as a liquid crystal device or a semiconductor device is charged, and a plasma generator for generating plasma by exciting a gas in the reactor By controlling the gas supply unit that supplies gas into the reactor, the gas exhaust unit that exhausts gas from the reactor, and the operation of the gas supply unit and the operation of the gas exhaust unit in conjunction with each other, An operation control method for a plasma reactor system having an instantaneous gas switching unit that instantaneously switches a gas in a reactor to a desired gas type, its concentration and pressure, and issues a plasma generation start command to the plasma generation unit Then, a switching command from the inert gas to the process gas is given to the instantaneous gas switching unit. Here, the “plasma generation start command” can be realized by sending a power-on command signal to the plasma generator.
[0013]
According to such a configuration, since the process gas introduced into the reaction furnace is immediately converted into plasma and contributes to the plasma reaction process, the use efficiency of the process gas is improved, and the manufacturing cost is reduced accordingly. In addition, since the waiting time before the start of the reaction process can be greatly reduced, productivity is improved by shortening the TAT (Turn-Around Time) of the process.
[0014]
The operation control method of the plasma reactor system of the present invention viewed from another aspect includes a reactor in which a processing object such as a liquid crystal device or a semiconductor device is charged, and a gas in the reactor is excited to generate plasma. A plasma generator, a gas supply unit that supplies gas into the reactor, a gas exhaust unit that exhausts gas from the reactor, and the operation of the gas supply unit and the operation of the gas exhaust unit are linked. And controlling the gas in the reactor instantaneously to a desired gas type, its concentration and pressure, and an operation control method for a plasma reactor system having an instantaneous gas switching unit. On the other hand, after giving a switching command from process gas to inert gas, a plasma generation stop command is given to the plasma generation unit. Here, the “plasma generation stop command” can be realized by sending a power-off command signal to the plasma generator.
[0015]
According to such a configuration, when the plasma reaction process is completed, the supply of the process gas is immediately stopped, and then a plasma generation stop command is promptly given to the plasma generator, so that the process gas that does not contribute to the plasma reaction is wasted. Therefore, it is possible to reduce the manufacturing cost by improving the utilization efficiency of the process gas. In addition, since the waiting time after the completion of the reaction process can be significantly reduced, productivity is improved by shortening the TAT (Turn-Around Time) of the process.
[0016]
The operation control method of the plasma reactor system of the present invention viewed from another aspect includes a reactor in which a processing object such as a liquid crystal device or a semiconductor device is charged, and a gas in the reactor is excited to generate plasma. A plasma generator, a gas supply unit that supplies gas into the reactor, a gas exhaust unit that exhausts gas from the reactor, and the operation of the gas supply unit and the operation of the gas exhaust unit are linked. Is a method for controlling the operation of a plasma reactor system having an instantaneous gas switching unit that instantaneously switches the gas in the reactor to a desired gas type, its concentration and pressure, The generation start command and the switching command from the inert gas to the process gas for the instantaneous gas switching unit are given almost simultaneously.
[0017]
According to such a configuration, the supplied process gas immediately contributes to the plasma reaction process, and at the start of the plasma reaction process, power is not wasted, thereby improving productivity and the process. In addition to gas savings, it is possible to pursue cost reductions to the utmost through saving energy.
[0018]
The operation control method of the plasma reactor system of the present invention viewed from another aspect includes a reactor in which a processing object such as a liquid crystal device or a semiconductor device is charged, and a gas in the reactor is excited to generate plasma. A plasma generator, a gas supply unit that supplies gas into the reactor, a gas exhaust unit that exhausts gas from the reactor, and the operation of the gas supply unit and the operation of the gas exhaust unit are linked. Is a method for controlling the operation of a plasma reactor system having an instantaneous gas switching unit that instantaneously switches the gas in the reactor to a desired gas type, its concentration and pressure, The generation stop command and the switching command from the process gas to the inert gas for the instantaneous gas switching unit are given almost simultaneously.
[0019]
According to such a configuration, the power is cut off and the plasma reaction process is completed, and the supply of the process gas is stopped, so that the process gas is not consumed wastefully, thereby improving the productivity and the process. In addition to gas savings, it is possible to pursue cost reductions to the utmost through saving energy.
[0020]
The operation control method of the plasma reactor system of the present invention viewed from another aspect includes a reactor in which a processing object such as a liquid crystal device or a semiconductor device is charged, and a gas in the reactor is excited to generate plasma. A plasma generator, a gas supply unit that supplies gas into the reactor, a gas exhaust unit that exhausts gas from the reactor, and the operation of the gas supply unit and the operation of the gas exhaust unit are linked. Is an operation control method of a plasma reactor system having an instantaneous gas switching unit that instantaneously switches a gas in the reactor to a desired gas type, its concentration and pressure, After giving a plasma generation start command, by giving a process gas switching command to the instantaneous gas switching unit, the process gas is switched while the plasma generating unit is in operation. And it is characterized in and.
[0021]
According to such a configuration, a plurality of types of process gases can be switched without sequential intervals to perform plasma reaction processing, thereby shortening a plurality of films having different properties on a substrate to be processed. Stack growth can be achieved in time.
[0022]
An operation control apparatus for a plasma reactor system according to the present invention includes a reaction furnace in which an object to be processed such as a liquid crystal device or a semiconductor device is charged, and a plasma generator for generating plasma by exciting a gas in the reactor. By controlling the gas supply unit that supplies gas into the reactor, the gas exhaust unit that exhausts gas from the reactor, and the operation of the gas supply unit and the operation of the gas exhaust unit in conjunction with each other, An operation control device of a plasma reactor system having an instantaneous gas switching unit that instantaneously switches a gas in a reactor to a desired gas type, its concentration and pressure, and issues a plasma generation start command to the plasma generation unit It is characterized by having a timing instruction means for giving a command for switching from an inert gas to a process gas to the instantaneous gas switching unit after being given.
[0023]
The operation control apparatus of the plasma reactor system of the present invention viewed from another aspect generates a plasma by exciting a reaction furnace in which a processing object such as a liquid crystal device or a semiconductor device is charged, and a gas in the reactor. A plasma generator, a gas supply unit that supplies gas into the reactor, a gas exhaust unit that exhausts gas from the reactor, and the operation of the gas supply unit and the operation of the gas exhaust unit are linked. An operation controller for a plasma reactor system having an instantaneous gas switching unit that instantaneously switches the gas in the reactor to a desired gas type, its concentration and pressure, and controls the instantaneous gas switching unit. On the other hand, there is provided a timing instruction means for giving a plasma generation stop command to the plasma generation unit after giving a command for switching from the process gas to the inert gas.
[0024]
The operation control apparatus of the plasma reactor system of the present invention viewed from another aspect generates a plasma by exciting a reaction furnace in which a processing object such as a liquid crystal device or a semiconductor device is charged, and a gas in the reactor. A plasma generator, a gas supply unit that supplies gas into the reactor, a gas exhaust unit that exhausts gas from the reactor, and the operation of the gas supply unit and the operation of the gas exhaust unit are linked. An operation control device for a plasma reactor system having an instantaneous gas switching unit that instantaneously switches the gas in the reactor to a desired gas type, its concentration and pressure, and controls the plasma to the plasma generation unit It has a timing instruction means for giving a generation start command and a switching command from an inert gas to a process gas to the instantaneous gas switching unit almost simultaneously.
[0025]
The operation control apparatus of the plasma reactor system of the present invention viewed from another aspect generates a plasma by exciting a reaction furnace in which a processing object such as a liquid crystal device or a semiconductor device is charged, and a gas in the reactor. A plasma generator, a gas supply unit that supplies gas into the reactor, a gas exhaust unit that exhausts gas from the reactor, and the operation of the gas supply unit and the operation of the gas exhaust unit are linked. An operation control device for a plasma reactor system having an instantaneous gas switching unit that instantaneously switches the gas in the reactor to a desired gas type, its concentration and pressure, and controls the plasma to the plasma generation unit It has a timing instruction means for giving a generation stop command and a switching command from process gas to inert gas to the instantaneous gas switching unit almost simultaneously.
[0026]
The operation control apparatus of the plasma reactor system of the present invention viewed from another aspect generates a plasma by exciting a reaction furnace in which a processing object such as a liquid crystal device or a semiconductor device is charged, and a gas in the reactor. A plasma generator, a gas supply unit that supplies gas into the reactor, a gas exhaust unit that exhausts gas from the reactor, and the operation of the gas supply unit and the operation of the gas exhaust unit are linked. An operation controller for a plasma reactor system having an instantaneous gas switching unit that instantaneously switches the gas in the reactor to a desired gas type, its concentration and pressure, and controls the plasma generation unit. After giving the plasma generation start command, the process gas is switched while the plasma generation unit is in operation by giving the process gas switching command to the instantaneous gas switching unit. Having a timing indicating means, it is characterized in.
[0027]
According to the above operation control apparatus, the operation control method described above can be automatically performed using a computer, a PLC, or the like.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a plasma reactor system according to the present invention and an operation control method and apparatus of the system will be described in detail with reference to the accompanying drawings.
A configuration example of the system of the present invention is shown in FIG. As shown in the figure, a plasma reactor system according to the present invention includes a process chamber (reactor) 1 for performing a plasma reaction, which is a process treatment reaction, and instantaneous gas switching with respect to the process chamber 1. An instantaneous gas switching unit 3 which is a gas system to be enabled, a plasma generating unit 2 for generating plasma in the process chamber 1, and a plasma / gas instructing execution timing of gas supply / stop and plasma power on / off A timing instruction unit 4 is included.
[0029]
In the process chamber 1, the process gas supplied from the instantaneous gas switching unit 3 is reacted with a substrate (wafer, glass substrate, etc.) in the process chamber 1 to perform film formation, etching, or the like. Plasma is generated in the process chamber 1 by the plasma generation unit 2 to apply excitation energy to the process gas, thereby realizing a (relatively) low temperature process treatment reaction.
[0030]
The instantaneous gas switching unit 3 and the gas supply / exhaust interlocking control unit 33 and the gas supply unit (in the figure, only one type of gas is illustrated, but actually, each type of gas is provided. ) 31 and a gas exhaust part 32. For example, as shown in FIG. 2, the gas supply unit 31 includes a pressure control type flow rate controller 311 and a valve 312, and controls the selection and supply amount of the supply gas.
[0031]
For example, as shown in FIG. 3, the pressure control type flow rate controller 311 includes a pressure measuring unit 52, a control valve 51, and an orifice 54. The measurement signal of the pressure measurement unit 52 is amplified by the amplification circuit 55 and then converted into a corresponding flow rate detection signal by the flow rate calculation unit 56. The flow rate detection signal is compared with the flow rate setting signal by the comparison control circuit 57, and a deviation signal thereof is obtained. The valve drive circuit 58 controls the opening degree of the control valve 51 in the direction in which the deviation signal decreases.
[0032]
This pressure control type flow controller 5 uses the principle that if the upstream pressure P1 is twice or more the downstream pressure P2, the fluid is in the sonic velocity range and is proportional to the upstream pressure. Since the flow rate is controlled by adjusting the pressure P1, the target gas flow rate can be instantaneously supplied even immediately after gas supply. The supply gas is selected by opening and closing the valve 312. That is, the pressure control type flow rate controller 311 and the stop valve 312 shown in FIG. 2 are provided for each gas type.
[0033]
For example, as shown in FIG. 2, the gas exhaust unit 32 includes an exhaust pump 322 having a purge port and a pressure control type flow rate controller 321. The exhaust pump 322 has a structure in which an inert purge gas is taken in from the purge port and exhausted at the same time in order to prevent adsorption and reaction of the reactive gas inside the pump. In this case, the sum of the flow rate from the chamber and the flow rate from the purge port is the pump exhaust speed (flow rate). Although it is impossible to instantaneously change the exhaust speed of the pump 322 that rotates at high speed internally, the pressure control type flow rate controller 321 changes the purge gas flow rate instantaneously, thereby exhausting from the chamber. The speed can be changed instantaneously.
[0034]
For example, as shown in FIG. 2, the gas supply / exhaust interlock control unit 33 includes a central processing unit 331, a main storage device 332, and an external interface 334. An external storage device 333 is added as necessary. The main storage device 332 holds a gas supply / exhaust timing control program, and the central processing unit 331 executes the gas supply / exhaust timing control program. As a result, the process gas supply / stop instruction is received from the external interface (eg, I / O, serial communication, field network, etc.) 334 or the main memory 332, and the instantaneous gas in the process chamber is linked with the gas supply / exhaust. Switching takes place.
[0035]
For example, as shown in FIG. 4, the gas supply amount is temporarily overshooted in the target shape at the start of gas supply (see FIG. 4A), and the gas concentration in the process chamber is sharply set to the target value. (See FIG. 4B), and the gas pressure in the process chamber that rises thereby is temporarily increased with a time delay Δt that takes into account the length of the gas piping and the like, and the gas exhaust speed of the process chamber is temporarily increased. (Refer to FIG. 4 (e)).
[0036]
With the configuration as described above, the instantaneous gas switching unit 3 controls the gas type, concentration, and pressure in the process chamber 1 by performing gas supply and exhaust in conjunction with the process chamber 1. The configuration of the instantaneous gas switching unit 3 was invented by the inventor of the present application, such as Tadahiro Omi, and has already been disclosed in detail in Japanese Patent Laid-Open No. 2000-200780.
[0037]
For example, as shown in FIG. 5A, the plasma generator 2 (21) includes a parallel plate electrode (configured by a plasma excitation electrode 212 and an electrode 213) and a high frequency power source 214 that supplies high frequency power thereto. And a shower plate 215 for supplying process gas and the like, and a chamber 211 for storing them. By applying high-frequency power to the supplied process gas through parallel plate electrodes, the process gas is excited and enters a plasma state. Further, instead of using high-frequency power, microwaves are generated from a microwave antenna 216 driven by a microwave drive circuit 217 and radiated into the chamber 211 as shown in FIG. There is also a method of exciting the process gas. By exciting the process gas by such a method, the process gas easily reacts with the processing object M such as a silicon substrate or a glass substrate.
[0038]
With the configuration described above, plasma generation / stop can be controlled by turning on / off the plasma power source (the high frequency power source 214 or the microwave driving circuit 217).
[0039]
For example, as shown in FIG. 6, the plasma / gas timing instruction unit 4 includes a main storage device 42, a central processing unit 41, and an external interface 46, and an input device 44 and a display device 45 as necessary. And an external storage device 43 are added. The main storage device 42 holds a timing execution instruction program and timing information, and the central processing unit 41 executes the timing execution instruction program. At this time, the plasma generator 2 and the instantaneous gas switching unit 3 are instructed to turn on / off the plasma power source and supply / stop the process gas through an external interface (for example, I / O, serial communication, field network, etc.) 46 based on the timing information. To tell. Input of timing information and a timing instruction program from the outside is performed by an input device (for example, a keyboard, a programming console, a handy terminal, etc.) 44 or an external interface 46, and is held in the main storage device 42 or once an external storage device. (For example, a hard disk, a silicon disk, a memory card, a magnetic disk, etc.) After being held in 43, it is used by being read into the main storage device. A display device (for example, a display) 45 displays timing information held as necessary, and uses it to check a set value.
[0040]
The plasma gas timing instruction unit 4 and the gas supply / exhaust interlock control unit 33 may be physically the same device. In this case, the central processing unit 331 and the central processing unit 41, the main storage unit 332 and the main storage unit 42, etc. are shared, and the process gas supply / stop instruction is sent from the program that functions as the process gas timing instruction unit. This can be realized by providing data via a main storage device to a program that functions as an interlock control unit.
[0041]
With the configuration as described above, the plasma / gas timing instruction section 4 instructs (commands) the execution timing (execution sequence) of turning on / off the plasma power source and supplying / stopping the gas, and controls the plasma and gas to perform the process. Proceed with the process.
[0042]
The instruction timing (plasma generation start / stop command, gas supply start / end command) will be described below with reference to FIGS. As shown in FIG. 7A, in the conventional operation control method, after the process gas is supplied (switched from the inert gas to the process gas) (step 710), the process gas in the process chamber is started. After waiting for the concentration and pressure to stabilize at the target values, the plasma power supply is turned on to start the process treatment reaction (step 711). At the end of the process treatment reaction, the plasma power supply is turned off to finish the process treatment reaction (step 712), and then the supply of the process gas is stopped (switching from the process gas to the inert gas) (step 713). Wait until the gas concentration and pressure in the process chamber are stabilized at the target values without performing processing for the next process (for example, opening the process chamber door and taking out the substrate). In this case, the time for waiting for the gas concentration and pressure in the chamber to stabilize is a wasteful time in which no processing is performed.
[0043]
On the other hand, in the present invention, as shown in FIG. 7B, after the plasma power source is turned on in the process chamber (step 720), the supply of the process gas is started (switching from the inert gas to the process gas). (Step 721). At the end of the process, the supply of process gas is stopped (switching from process gas to inert gas) (step 722), and then the plasma power supply is turned off (step 723). Unlike conventional systems, this is possible because the instantaneous gas switching unit 3 allows the gas concentration to instantaneously reach the target value in the process chamber 1 and be stabilized, and process processing can be executed from the moment when the gas is supplied. This is because. At this time, the process gas supply start (switching from the inert gas to the process gas) and the plasma power supply may be turned on almost simultaneously. Similarly, the process gas supply stop (switching from the process gas to the inert gas) Plasma power off may be performed almost simultaneously. Here, the process gas may be a mixture of a material gas (a gas used as a material such as a film generated by the process) and an inert gas, or may be only a material gas.
[0044]
Hereinafter, an embodiment of the plasma reaction process according to the present invention will be described. A BSG film (boron silicate glass film) is formed by plasma-excited CVD using the microwave plasma generator of FIG. The chamber capacity is 1 liter, the gas flow rate in the chamber is 100 cc / min in total, and the gas type is SiH. _Four , O ₂ , B ₂ H ₆ The purge gas was Ar, which is an inert gas. SiH in steady state _Four , O ₂ , B ₂ H ₆ The concentration ratios of 30, 50, and 20% were set as target values, respectively. The target pressure in the process chamber was 2 Torr, the plasma generating microwave was 2.45 GHz, the substrate temperature was 400 ° C., and the process treatment reaction time was 30 seconds.
[0045]
FIG. 8 is a diagram showing the interrelationship between gas supply, plasma power-on, and process processing reaction start time at the start of process processing according to the operation control method of the present invention. FIG. It is the figure which showed the mutual relationship of gas supply in this, plasma power-on, and process processing reaction start time.
[0046]
As shown in FIG. 11, in the case of the conventional operation control method in which the plasma power source is turned on after the process gas supply start (switching from the inert gas to the process gas), the gas concentration and pressure are started after the process gas supply starts. After waiting for a settling time (about 20 seconds), the plasma power supply is turned on to start the process treatment reaction (see FIG. 7A). Further, the process gas supplied during the waiting time is exhausted from the process chamber without being used for any process treatment reaction.
[0047]
As shown in FIG. 8, in the case of the operation control method of the present invention, first, the plasma power supply is turned on, and then the supply of the process gas is started (switching from the inert gas to the process gas). Thereby, the process treatment reaction is performed immediately after the start of the process gas supply.
[0048]
The process gas concentration changes stepwise and is set to the target value around 1 second or within 2 seconds (ie, instantaneously). This settling time may be as short as possible so that irregularities in film formation due to the transient state of the process gas concentration fall within an allowable range depending on the purpose of the process. The plasma power supply may be turned on and the process gas supply may be started almost simultaneously (for example, the plasma is turned on between the start of change of the process gas concentration and the settling).
[0049]
As described above, in the conventional method, the waiting time for starting the process treatment reaction is as high as 20 seconds with respect to the process treatment reaction time of 30 seconds. However, in the method of the present invention, the waiting time is zero and the process time is dramatically increased. In addition to being shortened, the process gas supplied during the waiting time becomes unnecessary, and thus the process gas can be effectively used.
[0050]
Next, SiO ₂ Another embodiment of the operation control method of the present invention applied to the film generation process will be described in detail with reference to FIGS. The feature of this embodiment is that the microwave generator shown in FIG. 5B is used as the plasma generator, and the gas is switched while the plasma power supply is turned on.
[0051]
That is, as shown in the time chart of FIG. 9, in the operation control method of this embodiment, first, the furnace in which the plasma power supply is shut off and argon gas (Ar), which is an inert gas, is flowed at a pressure of 1 Torr. The gas is switched from the argon gas (Ar) to the krypton gas (Kr) at the time (0 seconds) from the internal purge state, and further, at a time (10 seconds) 10 seconds later, plasma ignition (plasma generator) Power on). Then, a so-called plasma cleaning process is performed by the generated krypton plasma, and unnecessary hydrogen atoms (hydrogen termination) on the surface of the silicon wafer in the furnace, which is a processing target, are gradually removed.
[0052]
Furthermore, at a time (40 seconds) after 30 seconds, oxygen mixture that is a mixture of inert gas and process gas from krypton gas (Kr), which is an inert gas, with the plasma power supply turned on. Krypton gas (Kr / O ₂ : 97 to 3) gas is switched to start a film forming process, and a silicon dioxide film (SiO 2) is formed on the surface of the silicon wafer. ₂ ) Is gradually generated.
[0053]
Further, at a time (70 to 90 seconds) after about 30 to 50 seconds, the oxygen-mixed krypton gas (Kr / O) remains in a state where the plasma power supply is turned on. ₂ : 97: 3) to krypton gas (Kr) is switched, and the film forming process is completed.
[0054]
After that, when about 16 seconds elapse, the plasma is extinguished (the power supply to the plasma generator is shut off), and the gas is switched from krypton gas (Kr) to purge argon gas (Ar) with a slight delay. Is called. Thereafter, the above operation is repeated.
[0055]
FIG. 10 shows a graph showing the measurement results of the infrared spectrometer for explaining the residual change of the silicon surface termination hydrogen before and after the krypton plasma exposure. As is clear from the figure, as the exposure time of krypton plasma (Kr) increases to 1 second, 10 seconds, and 30 seconds, the residual hydrogen (terminal hydrogen) on the silicon surface decreases due to the so-called plasma cleaning action. confirmed.
[0056]
In the above example, the oxygen-mixed krypton gas (Kr / O) that is a mixture of the inert gas and the process gas is changed from the krypton gas (Kr) that is an inert gas while the plasma power supply is turned on. ₂ However, it should be understood that the film forming process is started after the plasma cleaning process, and this is only an example of the present invention. is there. That is, in the operation control method of the present invention, switching from the process gas (A) to the process gas (B) can also be performed with the plasma power source turned on. When such process gas switching during plasma generation is performed, a plurality of different types of films are stacked and grown on the substrate to be processed.
[0057]
As described above, according to the embodiment of the present invention, at the start of the process gas supply, there is no need to wait for the process gas concentration or pressure in the process chamber to stabilize at the target value. Since the process reaction can be started almost at the same time, it is possible to shorten the time of the entire process. Further, while waiting until the process gas concentration or pressure in the process chamber is stabilized at the target value, the process gas that has been wasted without being used for the process treatment reaction becomes unnecessary, and the utilization rate of the process gas can be improved. .
[0058]
Further, according to the embodiment of the present invention, there is no need to wait for the process gas concentration or pressure in the process chamber to stabilize at the target value even after the process gas supply is stopped. The utilization rate of process gas can be improved.
[0059]
Further, according to the embodiment of the present invention, when the process gas is switched, different process treatments can be continuously performed without stopping the reaction, so that the time of the entire process can be reduced.
[0060]
Further, when plasma is generated before supplying the process gas, cleaning can be performed to remove unnecessary atoms (films) on the inner wall of the process chamber and the surface of the silicon wafer to be processed, which become a contamination source of the wafer. Furthermore, there is an effect that a plurality of different types of films can be stacked and grown by performing gas switching while generating plasma.
[0061]
【The invention's effect】
As is apparent from the above description of the embodiment, according to the present invention, it is possible to realize a plasma reaction processing process necessary for production of a liquid crystal device or a semiconductor device with high productivity and low cost.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a system of the present invention.
FIG. 2 is a diagram illustrating a configuration example of an instantaneous gas switching unit.
FIG. 3 is a diagram illustrating a configuration example of a pressure control type flow rate controller.
FIG. 4 is a flowchart for explaining an example of gas supply / exhaust linked control;
FIG. 5 is a diagram illustrating a configuration example of a plasma generation unit.
FIG. 6 is a diagram illustrating a configuration example of a timing instruction unit.
FIG. 7 is a flowchart showing an operation control method of the present invention in comparison with a conventional method.
FIG. 8 is a graph showing changes in chamber pressure or gas concentration in one embodiment of the operation control method of the present invention.
FIG. 9 is a time chart showing a chamber gas switching mode in one embodiment of the operation control method of the present invention.
FIG. 10 is a graph for evaluating the results of plasma cleaning of a silicon surface according to an embodiment of the operation control method of the present invention.
FIG. 11 is a graph showing changes in chamber pressure or gas concentration in a conventional operation control method.
[Explanation of symbols]
1 Process chamber
2 Plasma generator
3 Instantaneous gas switching part
4 Plasma / gas timing indicator
5 Pressure-controlled flow controller
21 Plasma generator
31 Gas supply unit
32 Gas exhaust
33 Gas supply / exhaust interlock control unit
41 Central processing unit
42 Main memory
43 External storage
44 External interface
45 Display device
46 External interface
51 Control valve
52 Pressure measurement unit
53 Stop valve
54 Orifice
55 Amplifier circuit
56 Flow rate calculation circuit
57 Comparison control circuit
58 Valve drive circuit
211 chambers
212 Plasma excitation electrode
213 electrode
214 High frequency power supply
215 shower plate
216 Microwave antenna
217 Microwave drive circuit
311 Pressure control flow controller
312 valve
321 Pressure control type flow controller
322 Exhaust pump with purge port
331 Central processing unit
332 main storage
333 external storage device
334 External interface

Claims (8)

A reaction furnace in which an object to be processed such as a liquid crystal device or a semiconductor device is charged, a plasma generation unit for generating plasma by exciting the gas in the reaction furnace, and a gas supply for supplying gas into the reaction furnace The gas in the reactor and the concentration of the gas in the reactor by controlling the operation of the gas supply unit and the operation of the gas exhaust unit in conjunction with each other. And an operation control method for a plasma reactor system having a gas switching unit that switches to a pressure,
An operation control method for a plasma reactor system, characterized in that a plasma generation stop command is given to a plasma generation unit after giving a switch command from a process gas to an inert gas to a gas switching unit. A reaction furnace in which a processing object such as a liquid crystal device or a semiconductor device is charged, a plasma generation unit for generating plasma by exciting the gas in the reaction furnace, and various gases for supplying gas into the reaction furnace A gas supply unit according to the above, a gas exhaust unit for exhausting gas from the reaction furnace, and controlling the operation of the gas supply unit and the operation of the gas exhaust unit in conjunction with each other, thereby controlling the gas in the reactor An operation control method of a plasma reactor system having a gas switching unit that switches to a gas type and its concentration and pressure,
Select the gas supply unit corresponding to the gas to be supplied, and temporarily overshoot the inert gas supply amount at the start of supplying the inert gas through the gas supply unit, steeply target the inert gas concentration in the reactor The gas pressure in the reactor is increased from the process gas to the inert gas by temporarily raising the gas exhaust speed in the reactor with a time delay considering the gas pipe length. An operation control method for a plasma reactor system, characterized in that the plasma generation of the plasma generator is stopped after switching. A reaction furnace in which an object to be processed such as a liquid crystal device or a semiconductor device is charged, a plasma generation unit for generating plasma by exciting the gas in the reaction furnace, and a gas supply for supplying gas into the reaction furnace The gas in the reactor and the concentration of the gas in the reactor by controlling the operation of the gas supply unit and the operation of the gas exhaust unit in conjunction with each other. And an operation control method for a plasma reactor system having a gas switching unit that switches to a pressure,
After giving a plasma generation start command to the plasma generation unit, by giving a process gas switching command to the gas switching unit, the process gas is changed to a different type of process gas while the plasma generation unit is operating. The method of controlling the operation of the plasma reactor system, characterized in that switching is performed. A reaction furnace in which a processing object such as a liquid crystal device or a semiconductor device is charged, a plasma generation unit for generating plasma by exciting the gas in the reaction furnace, and various gases for supplying gas into the reaction furnace A gas supply unit according to the above, a gas exhaust unit for exhausting gas from the reaction furnace, and controlling the operation of the gas supply unit and the operation of the gas exhaust unit in conjunction with each other, thereby controlling the gas in the reactor An operation control method of a plasma reactor system having a gas switching unit that switches to a gas type and its concentration and pressure,
After selecting the gas supply unit corresponding to the gas to be supplied and starting the plasma generation of the plasma generation unit, temporarily overshoot the process gas supply amount at the start of supplying other types of process gas through the gas supply unit The process gas concentration in the reactor is suddenly changed to the target value, and the gas pressure in the reactor that rises as a result is increased with a time delay considering the gas pipe length and other factors. The plasma reactor is characterized in that the process gas is switched to a different type of process gas by temporarily pulling up the process gas to switch to a different type of process gas while the plasma generator is operating. System operation control method. A reaction furnace in which an object to be processed such as a liquid crystal device or a semiconductor device is charged, a plasma generation unit for generating plasma by exciting the gas in the reaction furnace, and a gas supply for supplying gas into the reaction furnace The gas in the reactor and the concentration of the gas in the reactor by controlling the operation of the gas supply unit and the operation of the gas exhaust unit in conjunction with each other. And a gas switching unit that switches to pressure, and an operation control device for a plasma reactor system,
A plasma reactor system comprising timing instruction means for giving a plasma generation stop command to the plasma generation unit after giving a switch command from the process gas to the inert gas to the gas switching unit Operation control device. A reaction furnace in which a processing object such as a liquid crystal device or a semiconductor device is charged, a plasma generation unit for generating plasma by exciting the gas in the reaction furnace, and various gases for supplying gas into the reaction furnace A gas supply unit according to the above, a gas exhaust unit for exhausting gas from the reaction furnace, and controlling the operation of the gas supply unit and the operation of the gas exhaust unit in conjunction with each other, thereby controlling the gas in the reactor An operation control device for a plasma reactor system having a gas type, a gas switching unit for switching to a concentration and pressure thereof,
Select the gas supply unit corresponding to the gas to be supplied, and temporarily overshoot the inert gas supply amount at the start of supplying the inert gas to the gas switching unit through the gas supply unit, so that the inert gas in the reaction furnace Process by changing the gas concentration sharply to the target value and temporarily increasing the gas exhaust speed in the reactor with a time delay considering the gas pipe length etc. An operation control apparatus for a plasma reactor system, comprising: a timing instruction unit that gives a plasma generation stop command to a plasma generation unit after giving a command to switch from gas to inert gas. A reaction furnace in which an object to be processed such as a liquid crystal device or a semiconductor device is charged, a plasma generation unit for generating plasma by exciting the gas in the reaction furnace, and a gas supply for supplying gas into the reaction furnace The gas in the reactor and the concentration of the gas in the reactor by controlling the operation of the gas supply unit and the operation of the gas exhaust unit in conjunction with each other. And a gas switching unit that switches to pressure, and an operation control device for a plasma reactor system,
After giving a plasma generation start command to the plasma generation unit, a process gas switching command is given to the gas switching unit, so that the process gas is changed to another type of process gas while the plasma generation unit is operating. An operation control device for a plasma reactor system, characterized by comprising timing instruction means for switching between the two. A reaction furnace in which a processing object such as a liquid crystal device or a semiconductor device is charged, a plasma generation unit for generating plasma by exciting the gas in the reaction furnace, and various gases for supplying gas into the reaction furnace A gas supply unit according to the above, a gas exhaust unit for exhausting gas from the reaction furnace, and controlling the operation of the gas supply unit and the operation of the gas exhaust unit in conjunction with each other, thereby controlling the gas in the reactor An operation control device for a plasma reactor system having a gas type, a gas switching unit for switching to a concentration and pressure thereof,
After selecting a gas supply unit corresponding to the gas to be supplied and giving a plasma generation start command to the plasma generation unit, the process is started when another type of process gas is supplied to the gas switching unit through the gas supply unit. Temporarily overshoot the gas supply amount and change the process gas concentration in the reactor sharply to the target value, and the gas pressure in the reactor that rises as a result takes into account the gas piping length, etc. By giving a command to switch from process gas to different types of process gas by temporarily raising the gas exhaust speed in the reactor with a delay, different types of processes can be performed while the plasma generator is operating. An operation control device for a plasma reactor system, characterized by comprising timing instruction means for switching to gas.

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