KR100481794B1 - Gas providing system of ALD process module - Google Patents

Abstract

The present invention relates to a gas supply system applied to an Atomic Layer Deposition (ALD) process module for depositing a thin film on an upper surface of a wafer by an atomic layer deposition method. A gas supply system connecting a chamber defining a reaction region in which a wafer is seated therein, and supplying the gaseous material into the chamber, comprising: a gas supply pipe connecting the gas storage device and the chamber; An auxiliary storage device installed in the middle of the gas supply pipe and configured to primarily store gaseous substances supplied from the gas storage device; It provides a gas supply system including a valve for regulating the inflow of the gaseous material stored in the secondary storage device into the chamber.

Description

Gas providing system of ALD process module

The present invention relates to a gas supply system included in a semiconductor manufacturing apparatus, and more particularly, to an Atomic Layer Deposition (ALD) process module for depositing a thin film on an upper surface of a wafer by an atomic layer deposition method. It relates to a gas supply system.

In recent years, with the development of science, the field of new materials, which enables the development and processing of new materials, has been rapidly developed, and the development results of these materials are driving the development of the semiconductor industry.

A semiconductor device is a large scale integration (LSI) that is realized through a process of depositing and patterning a plurality of thin films on a wafer, which is a substrate, and depositing such thin films. The semiconductor manufacturing process, such as patterning, is generally performed in a process module.

Each of the semiconductor manufacturing process modules has various forms according to a desired process, but as shown in FIG. 1, a chamber 20 defining a sealed reaction region in which a wafer is seated therein is commonly shown in FIG. 1. And a gas storage device 40 for storing gaseous materials necessary for the semiconductor manufacturing process to be carried out in the chamber 20.

The chamber 20 includes a decompression means such as an inlet pipe 22 connected to the above-described gas storage device, a discharge pipe 24 for discharging the residual gaseous material therein, and a pump P installed at an end thereof. Bar, first, after the wafer is introduced into the chamber 20 and closed, the pressure inside the chamber 20 is adjusted through pressure reduction means such as a pump P installed at the end of the discharge tube 24, and then the inflow pipe Through the 22 to induce a chemical reaction of the gaseous material supplied into the chamber 20 to process the wafer.

At this time, as a method of depositing a thin film on the upper surface of the wafer through chemical reaction of gaseous material, an atomic layer deposition method, abbreviated as ALD (ALD: Atomic Layer Deposition) method, has been developed. In addition, the present invention is widely used in the semiconductor manufacturing process because it has the advantage of realizing a thin film having excellent uniformity and step coverage characteristics.

The atomic layer deposition method is similar to the general chemical vapor deposition method (CVD: Chemical Vapor Deposition) in that a chemical reaction between two or more gaseous materials, but the general chemical vapor deposition method is a reaction in which a wafer is usually present Unlike the simultaneous inflow of a plurality of gaseous materials into the region and the deposition of their reaction products on the surface from above the wafer, there is a big difference in that the reaction sites at which gaseous reactions occur are limited only to the wafer surface.

Therefore, a plurality of gaseous materials are sequentially introduced into the reaction zone in which the wafer to be deposited is present, and a purge process of removing residual gaseous materials in the chamber before and after each gaseous inflow step is performed. This is required, for example, it is described for each process that proceeds when the thin film of the A + B compound to be deposited on the surface of the object through the atomic layer deposition method.

First, a first sub step of adsorbing the A material on the surface of the object by introducing a gaseous material containing A into the reaction region in which the wafer, which is the object exists, is followed. A second sub-step, which is a first purge for removing all residual gas in the reaction zone except for the above, is performed.

This removes all remaining gaseous material in the reaction zone and then proceeds to the third sub-step of introducing gaseous material containing B into the reaction zone, where an adsorption layer of A material is present on the top surface of the wafer. Therefore, a part of the B material included in the gaseous material introduced into the reaction zone reacts with the A material on the surface of the wafer to form a thin film of A + B.

Thereafter, a second purge process for removing all the gaseous substances present in the chamber is performed as a fourth sub-step. When the first to fourth sub-steps are performed in order, the surface of the wafer is an A + B compound. A thin film having a very thin thickness is deposited, thereby completing the process by sequentially repeating the thin film deposition cycle defined in the above-described first to fourth sub-steps several to several thousand times until the thin film having the desired thickness is realized.

Therefore, when FIG. 1 is an ADL process module for depositing a thin film on the upper surface of the wafer through the atomic layer deposition method, the gas storage device is the first corresponding to the gaseous material containing the A component in the above-described example, respectively. A first source storage device 42a for storing the source gas S1, a first purge gas storage device 42b for storing the first purge gas P1, and a second material corresponding to a gaseous material including a B component The second source material storage device 42c for storing the source gas S2 and the second purge gas storage device 42d for storing the second purge gas P2 are respectively divided.

In addition, the gas storage devices (42a, 42b, 42c, 42d) is usually provided with a flow rate regulating device for regulating the flow rate of each gaseous material, respectively, so that the first and second source gas (S1, S2), and the first and second Accurately control the amount of the second purge gas (P1, P2) and supply it to the chamber 20, the first to fourth MFC (MFC: Mass Flow Controller) (44a, 44b, 44c, 44d) shown That is it.

At this time, since each of the gaseous material should be introduced into the chamber 20 in sequence according to the time and order, the first to fourth FM (44a, 44b, 44c, 44d) and the inlet pipe 22 of the chamber 20 In between, a gas supply system 60 including a plurality of valves is provided.

That is, as shown in the drawing, the first source gas S1 stored in the first source gas storage device 42a is introduced into the chamber 20 by the first valve V1 which is a general on / off control valve. Inflow is interrupted, and similarly, the first purge gas P1 is the second valve V2, the second source gas S2 is the third valve V3, and the second purge gas P2 is the fourth valve V4. In order to determine the order and time to be introduced into the chamber 20, respectively.

On the other hand, a general MFC device has a function of discharging a predetermined amount of gaseous material within a given time, and as described above, when the supply time and sequence of each gaseous material are simply controlled by an on / off valve, the valve is closed. When the discharge pressure of the MFC is too high when the valve is opened, a large amount of gaseous substances are supplied to the chamber 20 at a time is frequently observed.

Accordingly, in the gas supply system 60 included in the ordinary ADL process module, when any one of the first to fourth valves V1, V2, V3, and V4 is turned off, the gaseous material discharged from the corresponding MFC is discharged. To discharge pressure into the pressure reducing means such as the pump P, respectively, the first MFC 44a and the first valve V1, the second MFC 44b and the second valve V2, and the third FM. First through fourth bypass pipes 62, 64, 66, branched between 44c and third valve V3, fourth MPC 44d and fourth valve V4; 68) are installed, and the fifth to eighth valves V5, V6, V7, and V8, which are on / off control valves, are respectively provided in the first to fourth bypass pipes 62, 64, 66, and 68. It is installed.

That is, the configuration of the gas supply system 60 included in the general ADL process module includes a first valve V1 for intermittently intercepting the first source gas S1 supplied from the first FM 44a to the chamber 20. ), The second valve V2 intermittently intercepting the first purge gas P1 supplied from the second FM 44B to the chamber 20, and the third 20 MPC 44c is introduced into the chamber 20. Third valve V3 for controlling the second source gas S2 to be used, and fourth valve V4 for regulating the second purge gas P2 flowing into the chamber 20 from the fourth MPC 44c. And are branched between the first to fourth MFCs 44a, 44b, 44c, and 44d and the first to fourth valves V1, V2, V3, and V4, respectively, to be connected to the pump P. The first to fourth bypass pipes (62, 64, 66, 68) and the first to fourth bypass pipes (62, 64, 66, 68) are respectively mounted to be delivered to the pump (P) 5th to 8th to regulate gaseous substances The valves V5, V6, V7, and V8 are included.

Accordingly, any one of the fifth to eighth valves V5, V6, V7, and V8 corresponding to each of the first, second, third, and fourth valves V1, V2, V3, and V4 is turned off. By turning on, the discharge pressure of the 1st-4th MFCs 44a, 44b, 44c, 44d is regulated uniformly.

For reference, in one thin film deposition cycle in which the first to fourth sub-steps are sequentially performed once through a general ADL process module, the respective valve driving relationships are summarized in Table 1, First valve V1, fifth valve V5, second valve V2, sixth valve V6, third valve V3, seventh valve V7, fourth valve V4, and The eight valves V8 may be complementary to each other.

In this case, reference numerals n1 and n2 of FIG. 1 denote a first node for introducing the first and second source gases into one inlet pipe 22, and for the first and second purge gases to flow therein, respectively. The second node is shown, and V1 to V8 recorded in the following table are used as symbols representing valves, respectively.

<Table 1>

V1 V2 V3 V4 V5 V6 V7 V8 First substep On off off off off On On On Second substep off On off off On off On On Third substep off off On off On On off On Fourth substep off off off On On On On off

However, the gas supply system 60 of such a general ADL process module includes a very large number of valves V1 to V8, and its structure and operation are very complicated, and it is necessary to enlarge a footprint print for installation. As a result, it is a cause for raising the manufacturing cost of a semiconductor element.

In addition, the use of such a plurality of valves to increase the probability of malfunction and eventually reduce the process reliability, one of the methods for reducing the number of valves, a pair of valves that are complementary to each other in Fig. Valve V1 and fifth valve V2, second valve V2 and sixth valve V6, third valve V3 and seventh valve V7, fourth valve V4 and eighth valve Instead of (V8), a method of using a general two-way valve may be considered, which has a limitation that cannot be an effective response given the specificity of the ADL process.

In other words, a typical two-way valve is installed at a confluence point where three pipes meet each other, and has only a divert function for flowing a fluid supplied from one pipe into a selected path of any of the other two pipes. When the valve is applied to the gas supply system of the ADL process module, although the number of valves may be somewhat reduced, there is no significant change in the structure of the overall gas supply system itself.

In addition, the flow must be interrupted for a short time in changing the direction of each two-way valve, and the interruption of the gas flow exerts excessive pressure on the FM, and in particular, repeats the same process several to several thousand times. Given the nature of the process, it is a fatal drawback that reduces productivity.

In addition, since the driving of each two-way valve also has to be performed sequentially, this also complicates the semiconductor manufacturing process. Thus, even if there is a high possibility of malfunction and the configuration is complicated, many on / off valves V1 to V8 have been It is used to interwork with each other.

Disclosure of Invention The present invention has been made to solve the above problems, and an object thereof is to provide a gas supply system of an ADL chamber, which has a simpler structure and can manufacture a reliable semiconductor device.

The present invention provides a gas supply system for supplying the gaseous material into the chamber by connecting a gas storage device for storing the gaseous material and a chamber defining a reaction zone in which a wafer is seated therein, to achieve the above object. As a gas supply pipe for connecting the gas storage device and the chamber; An auxiliary storage device installed in the middle of the gas supply pipe and configured to primarily store gaseous substances supplied from the gas storage device; It provides a gas supply system including a valve for regulating the inflow of the gaseous material stored in the secondary storage device into the chamber.

In particular, the valve is characterized in that the on / off control valve, a gas flow rate control device is installed between the gas storage device and the auxiliary storage device.

In addition, the gas storage device, the auxiliary storage device and the valve is three or more, respectively, characterized in that each of the valves are repeatedly driven several times each sequentially.

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

2 is a schematic structural diagram of an ADL process module including a gas supply system according to the present invention, which includes a chamber 120 defining a sealed reaction area in which a wafer is placed, and the chamber 120. And a gas storage device 140 for storing a gaseous material necessary for the semiconductor manufacturing process, which is carried out in the 120. In particular, the chamber 120 includes an inlet pipe 122 connected to the gas storage device 140 described above. And a pressure reducing means such as a discharge pipe 124 for discharging the residual gaseous material therein and a pump P installed at an end thereof, may be referred to as a typical case.

In addition, the gas storage device 140 may include a first source gas storage device 142a for storing a first source gas, a first purge gas storage device 142b for storing a first purge gas, and a second source gas, respectively. The second source gas storage device 142c for storing and the second purge gas storage device 142d for storing the second purge gas, respectively, are divided into the respective gas storage devices 142a, 142b, 142c, and 142d. The first to fourth Mass Flow Controllers 144a, 144b, 144c, and 144d are connected in a one-to-one correspondence so as to control the amount of gaseous material discharge.

When the wafer is introduced into the chamber 120 and then sealed, the internal pressure of the chamber 120 is adjusted through pressure reduction means such as a pump P installed at the distal end of the discharge pipe 124. By processing the wafer through the chemical reaction of the gas material supplied into the chamber 120 through the), wherein the first to the fourth (FM) so as to supply each gas material in sequence according to time and order ( Between the 144a, 144b, 144c, and 144d and the inlet pipe 122 of the chamber 120, a gas supply system 160 according to the present invention is installed.

At this time, in particular, the gas supply system 160 is provided with first to fourth valves V1 'and V2' V3 'V4' which merely perform on / off functions, respectively, which are the first MFCs 144a. The first valve (V1 ') for controlling the first source material to be introduced into the chamber 120 through the) and the first to control the first purge material introduced into the chamber 120 through the second MFC 144b The second valve V2 ', the third valve V3' for controlling the second source material introduced into the chamber 120 through the third FM 144c, and the chamber through the fourth FM 144d. This is the fourth valve V4 ′ which controls the second purge material entering 120.

In comparison with FIG. 1, which shows a gas supply system included in a general ADL process module, the gas supply system according to the present invention includes the first to fourth bypass pipes 62, 64, 66, and 68. It can be seen that the fifth to eighth valves V5, V6, V7, and V8 respectively mounted are omitted. Instead, in the present invention, the first to fourth auxiliary storage devices 182 in the gas supply system 140 are replaced. , 184, 186, 188).

That is, the gas supply system 140 according to the present invention includes first to fourth valves V1 ′, V2 ′, and V3 connected to the first to fourth MFCs 144a, 144b, 144c, and 144d in one-to-one correspondence. ', V4') includes a first auxiliary storage device 182, a second auxiliary storage device 184, a third auxiliary storage device 186, and a fourth auxiliary storage device 188, respectively. The first to fourth auxiliary storage devices 182, 184, 186, and 188 may be gaseous materials discharged from the corresponding first to fourth FMs 144a, 144b, 144c, and 144d, respectively. It serves as a tank to store the primary.

In addition, the internal volume of each secondary storage device is preferably characterized in that it is enough to store the gas discharged from the MFC from the off after the corresponding valve is turned on again, according to the present invention A cross section of a first auxiliary storage device 182, which is one of the first to fourth auxiliary storage devices 182, 184, 186, and 188, will be described with reference to FIG. 3 and FIG. 2, which will be described below. The same applies to the second to fourth auxiliary storage tanks 184, 186, and 188.

As described above, the first auxiliary storage device 182 included in the gas supply system 140 according to the present invention is a simple tank that primarily stores the first source gas S1 supplied from the first MFC 144a. As described above, it is possible to provide a storage device having a certain amount of contents, which may be mounted between the first MFC 144a and the first valve V1 '. Likewise, a part of the connecting pipe connecting the first MFC 144a and the first valve V1 'may be greatly expanded, and any shape, material, and configuration capable of storing gaseous material therein may also be configured. The possibility will be seen from the description below.

The first auxiliary storage device 182 serves to primarily store the gaseous material flowing therein, and its volume starts from the time when the first valve V1 'is turned off and the second to fourth valves. Has a size sufficient to store the first source gas S1 discharged from the first MFC 144a until the first valve V1 'is turned on again after being turned on and off in turn. The first to fourth valves during one thin film deposition cycle defined by sequentially performing the first to fourth sub-steps one by one through the ADL process module including the gas supply system according to the present invention. It will be described in comparison with the driving of V1 'V2' V3 'V4').

TABLE 2

V1 ' V2 ' V3 ' V4 ' First substep On off off off Second substep off On off off Third substep off off On off Fourth substep off off off On

In the case where the first valve V1 'is turned on, the first auxiliary storage device 182 according to the present invention is in a low pressure state close to a vacuum in the chamber 120 when the first sub-step is performed. The first source gas S1 supplied through the first MFC 144a is introduced into the chamber 120 without any limitation.

Thereafter, when the first valve V1 'is turned off to enter the second sub-step and turn on the second valve V2' at the same time, the first sub-step is supplied from the first MFC 144a. The first source material S1 starts to be stored in the first auxiliary storage device 182 according to the present invention, after which the second to fourth sub-steps are sequentially performed to complete the first thin film deposition cycle.

Thereafter, the first source gas S1 is filled in the first auxiliary storage device 182 until just before the first valve V1 ′ is turned on in the second thin film deposition cycle, followed by the first valve V1. As the first source material stored in the first auxiliary storage device 182 is supplied to the inside of the chamber 120 in the low pressure environment as the ') is turned on, the first valve ( V2 ') is turned off to repeat the above-described process.

Accordingly, the first to fourth auxiliary storage devices 182, 184, 186, and 188 according to the present invention serve as a bypass used in a general ADL process module.

The present invention is a gas supply system included in a general AL process module, the first to fourth bypass pipe and the first to fourth auxiliary storage capable of performing the role of the first to fourth valves respectively attached thereto By providing the device, it is possible to greatly reduce the number of valves included in the gas supply system as a whole.

Therefore, the structure of the gas supply system can be simplified, greatly reducing the possibility of malfunction, and the area for installation is also small, which has economic advantages. In addition, each of the first and fourth auxiliary storage devices provided by the present invention simply serves as a storage tank that primarily stores gas, thereby enabling a more reliable semiconductor manufacturing process.

1 is a schematic structural diagram of an ADL process module including a general gas supply system

2 is a schematic structural diagram of an ALD process module including a gas supply system according to the present invention;

3 is a cross-sectional view of a first auxiliary storage device included in a gas supply system according to the present invention.

<Description of the symbols for the main parts of the drawings>

120: chamber 122: inlet pipe

124: discharge pipe 140: gas storage device

144a, 144c: first and second source gas storage devices

144b, 144d: first and second purge gas storage devices

144a, 144b, 144c, 144d: first to fourth MFC

160: gas supply system

182, 184, 186, 188: first to fourth auxiliary storage device

V1 ', V2', V3 ', V4': First to fourth valve P: Pump

Claims (5)

A gas supply system for supplying the gaseous material into the chamber by connecting a gas storage device for storing the gaseous material and a chamber defining a reaction region in which a wafer is seated therein, A gas supply pipe connecting the gas storage device and the chamber; An auxiliary storage device installed in the middle of the gas supply pipe and configured to primarily store gaseous substances supplied from the gas storage device; A valve for controlling the inflow of gaseous substances stored in the auxiliary storage device into the chamber Gas supply system comprising a The method according to claim 1, The valve is a gas supply system is an on / off control valve The method according to claim 1, Gas supply system is installed between the gas storage device and the auxiliary storage device gas flow rate control device The method according to claim 1, The gas storage device, the auxiliary storage device and the valve are each three or more equal number gas supply system The method according to claim 4, The gas supply system repeats each of the valves driving several times sequentially.