# Patent

## Title
Method for performing uniform processing in gas system-sharing multiple reaction chambers

## Abstract

A method for performing uniform processing in multiple reaction chambers includes (a) conducting a cycle constituted by steps in each reaction chamber according to the order of the reaction chambers at which the steps are conducted; and then (b) conducting the steps in each reaction chamber after changing the immediately prior order of the reaction chambers at which the steps are conducted; and then (c) repeating process (b) until a target treatment is complete at the multiple reaction chambers. The target treatment conducted on a substrate in each reaction chamber is the same.

## Background
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a method for performing uniform processing in multiple reaction chambers sharing a gas supply system.
2. Description of the Related Art
In order to increase throughput of processed wafers, multiple wafers are loaded in a reaction chamber and processed simultaneously, by executing batch programs. However, it is difficult to perform processing with high precision using batch programs. On the other hand, if a single wafer is loaded in a reaction chamber and processed, the process can be controlled with high precision, but throughput suffers. If multiple reaction chambers of the single-wafer processing type are combined and share a process gas supply system, by operating the multiple reaction chambers simultaneously, throughput can be increased. However, when the Multiple reaction chambers share a common process gas supply system provided with a common bottle (reservoir) containing a liquid precursor, and a vaporized precursor is supplied to the multiple reaction chambers simultaneously, because of differences in pipe length from the bottle to each reaction chamber, differences in conductance of the supply line for each reaction chamber, etc it is difficult to supply a vaporized precursor equally to all the multiple reaction chambers, creating variations among the reaction chambers in terms of deposition rate, film uniformity, film composition, etc. The above variation problem in the multiple reaction chambers of the single-wafer processing type can greatly be alleviated, by conducting the process in the multiple reaction chambers in sequence, i.e., starting the process in the multiple reaction chambers in sequence with a certain delay (supplying a vaporized precursor to the multiple reaction chambers in sequence at shifted timing) wherein the process is repeated in the sequence to process multiple wafers in the multiple reaction chambers. The above sequential process works well to reduce variations in film quality among the multiple reaction chambers if the precursor has a relatively low vapor pressure, i.e., the quantity of the precursor is relatively low and thus, the precursor can readily be purged from the gas supply system.
However, if the precursor has a high vapor pressure (e.g., trimethyl phosphate, TMPI, has a vapor pressure of 2.27 kPa at 25° C., whereas bisdiethyiaminosilance, BDEAS, has a vapor pressure of 0.436 kPa at 25° C.), the quantity of the precursor is large, i.e., it is difficult to fully purge the gas from the gas supply system. The present inventors discovered that when using a precursor having a high vapor pressure in a parallel cyclic processing system of multiple reaction chambers sharing a gas supply system, variations of film properties among the reaction chambers occurred depending on the order in which the reaction chambers started processing.
Any discussion of problems and solutions in relation to the related art has been included in this disclosure solely for the purposes of providing a context for the present invention, and should not be taken as an admission that any or all of the discussion was known at the time the invention was made.
SUMMARY OF THE INVENTION
Some embodiments provide a method for performing uniform processing in multiple reaction chambers comprising: (a) conducting a cycle constituted by steps in each reaction chamber according to the order of the reaction chambers at which the steps are conducted; and then (b) conducting the steps in each reaction chamber after changing the immediately prior order of the reaction chambers at which the steps are conducted; and then (c) repeating process (b) until a target treatment is complete at the multiple reaction chambers, said target treatment conducted on a substrate in each reaction chamber being the same. Above processes (a) to (c) can equally apply to a system comprising two or three or more reaction chambers without changing the principle of operation. Also, above processes (a) to (c) can equally apply to a process recipe including more than two steps in one cycle, i.e., one cyclic process unit.
In the above, by changing the order in which the reaction chambers are used for processing during the same target treatment, variations of film properties, for example, can effectively be suppressed. Changing the order of processing includes changing the order of the reaction chambers to which a precursor gas and/or a reactant gas is/are supplied, changing the order of the reaction chambers to which an RF power is applied, and/or changing the order of the reaction chambers in which purging is conducted. These changes can be independently conducted, and some of the steps can be conducted simultaneously. For example, the order of the reaction chambers to which a process gas is supplied is changed whereas an RF power is applied simultaneously to all the reaction chambers. In some embodiments, the repeating processes are those for forming a doped-film, a metal film, or a SiO film, or for trimming or etching a film. In some embodiments, because variations of film properties among reaction chambers can be controlled by changing the order of the reaction chambers in which a step in one cycle is conducted, by checking parameters indicative of variations of film properties downstream of the reaction chambers and feeding back the parameters to a control unit, a suitable order can be determined and the processing can be performed using the determined order, thereby improving uniformity of processing in all the reaction chambers. The above feedback control can be performed continuously.
For purposes of summarizing aspects of the invention and the advantages achieved over the related art, certain objects and advantages of the invention are described in this disclosure. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
Further aspects, features and advantages of this invention will become apparent from the detailed description which follows.



BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of this invention will now be described with reference to the drawings of preferred embodiments which are intended to illustrate and not to limit the invention. The drawings are greatly simplified for illustrative purposes and are not necessarily to scale.
FIG. 1 is a schematic view of a dual-chamber plasma-enhanced atomic layer deposition (PEALD) apparatus to which an embodiment of the present invention is applied.
FIG. 2 illustrates a schematic process sequence applied to a dual-chamber PEALD apparatus according to a comparative embodiment.
FIG. 3 illustrates a schematic process sequence applied to a dual-chamber PEALD apparatus according to a comparative embodiment.
FIG. 4 illustrates a schematic process sequence applied to a dual-chamber PEALD apparatus according to another embodiment of the present invention.
FIG. 5 illustrates a schematic process sequence applied to a dual-chamber PEALD apparatus according to still another embodiment of the present invention.
FIG. 6 illustrates a schematic process sequence applied to a dual-chamber PEALD apparatus according to yet another embodiment of the present invention.
FIG. 7 illustrates a schematic process sequence applied to a triple-chamber PEALD apparatus according to a comparative embodiment.
FIG. 8 illustrates a schematic process sequence applied to a triple-chamber PEALD apparatus according to an embodiment of the present invention.
FIG. 9 illustrates a detailed process sequence applied to a dual-chamber PEALD apparatus according to a comparative embodiment.
FIG. 10 illustrates a detailed process sequence applied to a dual-chamber PEALD apparatus according to an embodiment of the present invention.
FIG. 11 is a schematic view of a dual-chamber PEALD apparatus to which an embodiment of the present invention is applied.
FIG. 12 illustrates step 1 of a process sequence in the dual-chamber PEALD apparatus illustrated in FIG. 11 according to an embodiment of the present invention.
FIG. 13 illustrates step 2 of a process sequence in the dual-chamber PEALD apparatus illustrated in FIG. 11 according to an embodiment of the present invention.
FIG. 14 illustrates step 3 and step 5 of a process sequence in the dual-chamber PEALD apparatus illustrated in FIG. 11 according to an embodiment of the present invention.
FIG. 15 illustrates step 4 and step 6 of a process sequence in the dual-chamber PRAM apparatus illustrated in FIG. 11 according to an embodiment of the present invention.
FIG. 16 illustrates step 7 of a process sequence in the dual-chamber PEALD apparatus illustrated in FIG. 11 according to an embodiment of the present invention.
FIG. 17 is a graph showing a phosphorous concentration of a phosphorus silicon glass (PSG) film in a depth direction which was deposited in each reaction chamber of a dual-chamber PEALD apparatus according to a comparative embodiment.
FIG. 18 is a graph showing a phosphorous concentration of a phosphorus silicon glass (PSG) film in a depth direction which was deposited in each reaction chamber of a dual-chamber PEALD apparatus according to an embodiment of the present invention.
FIG. 19 shows the conditions under which a film was deposited in Example 1.



DETAILED DESCRIPTION OF EMBODIMENTS
In this disclosure, “gas” may include vaporized solid and/or liquid and may be constituted by a single gas or a mixture of gases. Likewise, an article “a” or “an” refers to a species or a genus including multiple species. In this disclosure, a process gas introduced to a reaction chamber through a showerhead may be comprised of, consist essentially of or consist of a precursor, a reactant gas, and a purge gas. The precursor and the reactant gas can react with each other in an excited state and can be introduced with another gas or a carrier gas such as a rare gas. A gas other than the process gas. i.e., a gas introduced without passing through the showerhead, may be used for, e.g., sealing the reaction space, which includes a seal gas such as a rare gas. In some embodiments, “film” refers to a layer continuously extending in a direction perpendicular to a thickness direction substantially without pinholes to cover an entire target or concerned surface, or simply a layer covering a target or concerned surface.
In this disclosure, “dual chambers” refers to two sections or compartments for processing wafers disposed closely to each other and viewed substantially as, e.g., positionally, structurally, functionally, and/or operationally, separated or isolated from each other, which include not only two separate chambers connected to each other side by side or vertically, but also two isolated regions disposed side by side or vertically in one common chamber. In this disclosure, a “module” refers to a standardized unit detachably attachable to a wafer-handling main chamber.
In this disclosure, any defined meanings do not necessarily exclude ordinary and customary meanings in some embodiments.
Further, in this disclosure, any two numbers of a variable can constitute a workable range of the variable as the workable range can be determined based on routine work, and any ranges indicated may include or exclude the endpoints. Additionally, any values of variables indicated (regardless of whether they are indicated with “about” or not) may refer to precise values or approximate values and include equivalents, and may refer to average, median, representative, majority, etc. in some embodiments.
In the present disclosure where conditions and/or structures are not specified, the skilled artisan in the art can readily provide such conditions and/or structures, in view of the present disclosure, as a matter of routine experimentation.
In all of the disclosed embodiments, any element used in an embodiment can be replaced with any elements equivalent thereto, including those explicitly, necessarily, or inherently disclosed herein, for the intended purposes. Further, the present invention can equally be applied to apparatuses and methods.
The embodiments will be explained with respect to preferred embodiments. However, the present invention is not limited to the preferred embodiments.
An embodiment provides a method for performing uniform processing in multiple reaction chambers sharing a first gas source and a second gas source, each reaction chamber having a gas inlet line through which a first gas from the first gas source, a second gas from the second gas source, and a purge gas are introduced into the reaction chamber, wherein a target treatment conducted in each reaction chamber is the same, said method comprising; (i) supplying the first gas to the multiple reaction chambers through the respective gas inlet lines in a supply order where the first gas is supplied to one of the multiple reaction chambers and then to another of the multiple reaction chambers; (ii) supplying the second gas to the multiple reaction chambers through the respective gas inlet lines in a supply order where the second gas is supplied to one of the multiple reaction chambers and then to another of the multiple reaction chambers; (iii) supplying the purge gas to the multiple reaction chambers through the respective gas inlet lines after every supply of the first gas and after every supply of the second gas so as to purge the first gas and the second gas, respectively, from the multiple reaction chambers and the gas inlet lines, and (iv) continuously repeating steps (i) to (iii) to complete the target treatment in the multiple reaction chambers, wherein the supply order of at least one of the first gas or the second gas is changed when the supply of the at least one of the first gas or the second gas is repeated. In this disclosure, “continuously” refers to without breaking a vacuum, without interruption as a timeline, without changing treatment conditions, or immediately thereafter.
The multiple reaction chambers may be two or three or more reaction chambers disposed side by side or vertically. For example, a dual-chamber reactor which may be a module may be used. The multiple reaction chambers share a first gas source and a second gas source, and each reaction chamber has a gas inlet line through which a first gas from the first gas source, a second gas from the second gas source, and a carrier gas (also functions as a purge gas) are introduced into the reaction chamber. Since at least part of a gas supply system is shared by the multiple reaction chambers, a problem may occur in evenly dividing a gas flow to the multiple reaction chambers when supplying a gas simultaneously to the multiple reaction chambers due to the differences in the piping length from the gas source to each reaction chamber and the differences in conductance of the piping. Thus, typically, a gas is supplied to the multiple reaction chambers in sequence without dividing a gas flow into multiple paths. However, even when supplying a gas in sequence, a flow path is different among the multiple reaction chambers, resulting in non-uniform gas supply among the multiple reaction chambers.
In some embodiments, the multiple reaction chambers share an exhaust system, and the pressure of each reaction chamber is controlled using the exhaust system.
In some embodiments, the multiple reaction chambers each comprise another gas line, through which an additive gas or inert gas is supplied to the multiple reaction chambers.
Typically, when the first gas source and the second gas source include bottles storing liquid compounds, respectively, vaporized gases of which are the first gas and the second gas, respectively, the difference in gas flow among the multiple reaction chambers may become more problematic since some precursors and reactants have a high vapor pressure, and thus, the quantity of the compounds is high, i.e., it is not easy to purge these compounds evenly from the multiple reaction chambers. In some embodiments, a first gas line from the first gas source is ramified and connected to each of the gas inlet lines of the multiple reaction chambers, and a second gas line from the second gas source is ramified and connected to each of the gas inlet lines of the multiple reaction chambers, wherein the first gas and the purge gas are introduced to the multiple reaction chambers through the first gas line, the lines ramified therefrom, and the gas inlet lines of the multiple reaction chambers, while the second gas and the purge gas are introduced to the multiple reaction chambers through the second gas line, the lines ramified therefrom, and the gas inlet lines of the multiple reaction chambers, wherein each ramified line is provided with a valve. In the above, the gas flows defined in steps (i) to (iii) can effectively be controlled using each valve. In some embodiments, the purge gas continuously flows alone or with the first gas through the first gas line, while the purge gas continuously flows alone or with the second gas through the second gas line. Since the first gas, the purge gas associated with the first gas, the second gas, and the purge gas associated with the second gas pass through the gas inlet line of each reaction chamber, a gas flow switching unit is required, in the gas flow switching unit, the route where each gas passes through the unit is different for each reaction chamber. Thus, when the process order of the reaction chambers to which each gas is supplied is fixed, the difference in gas flow among the reaction chambers is also fixed. By conducting steps (i) to (iv) described above, the difference in gas flow among the reaction chambers can be minimized.
The target treatment conducted in each reaction chamber is the same. In some embodiments, the repeating processes for the target treatment are those for forming a doped-film, a metal film, or a SiO film, or for trimming or etching a film. The number of gases, the type of gas, flow rate, gas excitation method, temperature, pressure, etc. can be determined according to the target treatment. A skilled artisan in the art can readily provide such conditions as a matter of routine experimentation.
In some embodiments, one cycle is comprised of steps (i) to (iii), and in step (Iv), the cycle is repeated wherein the supply order of at least one of the first gas or the second gas is changed per cycle. In some embodiments, the supply order of the second gas is changed per cycle while the supply order of the first gas is unchanged. In other embodiments, the supply order of each of the first gas and the second gas is changed per cycle. In some embodiments, one cycle is comprised of steps (i) to (iii), and step (ii) is repeated in the cycle wherein the supply order of the second gas is changed when step (ii) is repeated in the cycle, said cycle being repeated in step (iv). In some embodiments, a supply rate of the first gas is two or more times higher than a supply rate of the second gas.
In some embodiments, the method further comprises (iiia) applying RF power in the multiple reaction chambers after every step (iii). RF power can be applied to the multiple reaction chambers sequentially or simultaneously, in some embodiments, the multiple reaction chambers share an RF generator which generates RF power. In some embodiments, the target treatment is deposition of a film by plasma-enhanced atomic layer deposition (PEALD). Alternatively, the target treatment may be conducted by thermal ALD, radical-enhanced ALD, cyclic CVD, or any other cyclic processing, wherein a cycle is repeated 20 to 300 times (typically, 50 to 200 times), for example, to complete the target treatment.
In another aspect, an embodiment provides a method for performing uniform processing in multiple reaction chambers comprising: (a) conducting a cycle constituted by steps in each reaction chamber according to the order of the reaction chambers at which the steps are conducted; and then (b) conducting the steps in each reaction chamber after changing the immediately prior order of the reaction chambers at which the steps are conducted; and then (c) repeating process (b) until a target treatment is complete at the multiple reaction chambers, said target treatment conducted on a substrate in each reaction chamber being the same.
In some embodiments, the steps include a step of supplying a first gas and a step of supplying a second gas. In some embodiments, the first and second gases are supplied to one of the reaction chambers through a first common gas inlet line, and the first and second gases are supplied to another of the reaction chambers through a second common gas inlet line, wherein the first gas is supplied to a first gas line which is ramified and connected to the first and second common as inlet lines, and the second gas is supplied to a second gas line which is ramified and connected to the first and second common gas inlet lines.
Another embodiment provides a method for performing uniform processing in a first reaction chamber and a second reaction chamber wherein a target treatment conducted on a substrate in each reaction chamber is the same, wherein the target treatment is conducted by repeating step A and step B in this sequence, wherein steps A and B which are conducted at the first reaction chamber are referred to as steps A1 and B1, and steps A and B which are conducted at the second reaction chamber are referred to as steps A2 and B2, said method comprising: (a) conducting steps A1, A2, B1, and B2 in this order; and then (b) conducting the steps after changing the immediately prior order; and then (c) repeating process (b) until the target treatment is complete at the first and second reaction chambers.
The embodiments will be explained with reference to the drawings. The drawings are not intended to limit the present invention.
FIG. 1 is a schematic view of a dual-chamber plasma-enhanced atomic layer deposition (PEALD) apparatus to which an embodiment of the present invention is applied. The apparatus combines a plasma reactor and flow control valves, desirably in conjunction with controls programmed to conduct the sequences described below, which can be used in an embodiment of the present invention. In this figure, reaction chamber 1 (RC1) and reaction chamber 2 (RC2) are provided side by side and constitute a module. The reaction chambers 1, 2 share a bottle 7 (first gas source) and a bottle 8 (second gas source), and also an auto pressure controller 3 connected to an exhaust pump 4. Further, the reaction chambers 1, 2 share an RF generator 14. When the first gas is supplied to the reaction chamber 1 or the reaction chamber 2, a carrier gas (e.g., Ar) is provided through a mass flow controller 5 to the bottle 7 which contains a liquid for the first gas and is equipped with a heater, where a valve v2 is open whereas a valve v1 is closed. The carrier gas enters the bottle 7 and flows out therefrom with the vaporized liquid for the first gas, to a first gas line 9 via a valve v3. The first gas is constituted by a mixture of the active material (vaporized liquid for the first gas) and the carrier gas. The first gas line 9 is ramified to a gas inlet line 17 connected to the reaction chamber 1 and a gas inlet line 19 connected to the reaction chamber 2. The first gas flows through the gas line 9 and the gas inlet line 17 via a valve v7 provided between the gas line 9 and the gas inlet line 17 (a valve v8 provided between the gas line 9 and the gas inlet line 19 is closed), and enters the reaction chamber 1. When the valve v7 is closed and the valve v8 is open, the first gas flows through the gas line 9 and the gas inlet line 19 via the valve v8, and enters the reaction chamber 2. When the valve v1 is open and the valve v2 is closed, only the carrier gas flows through the gas line 9 and enters the reaction chamber 1 or 2 via the same route as the first gas, wherein the carrier gas functions as a purge gas.
When the second gas is supplied to the reaction chamber 1 or the reaction chamber 2, a carrier gas (e.g., Ar) is provided through a mass flow controller 6 to the bottle 8 which contains a liquid for the second gas and is equipped with a heater, where a valve v5 is open whereas a valve v4 is closed. The carrier gas enters the bottle 8 and flows out therefrom with the vaporized liquid for the second gas, to a second gas line 10 via a valve v6. The second gas is constituted by a mixture of the active material (vaporized liquid for the second gas) and the carrier gas. As with the first gas line 9, the second gas line 10 is ramified to the gas inlet line 17 connected to the reaction chamber 1 and the gas inlet line 19 connected to the reaction chamber 2, wherein the first and second gas lines 9, 10 share the gas inlet lines 17, 19. The second gas flows through the gas line 10 and the gas inlet line 17 via a valve v9 provided between the gas line 10 and the gas inlet line 17 (a valve v10 provided between the gas line 10 and the gas inlet line 19 is closed), and enters the reaction chamber 1. When the valve v9 is closed and the valve v10 is open, the second gas flows through the gas line 10 and the gas inlet line 19 via the valve v10, and enters the reaction chamber 2. When the valve v4 is open and the valve v5 is closed, only the carrier gas flows through the gas line 10 and enters the reaction chamber 1 or 2 via the same route as the second gas, wherein the carrier gas functions as a purge gas.
Additionally, separately from the first and second gases, oxygen, argon, and helium, for example, can be supplied from an oxygen mass flow controller 11, argon mass flow controller 12, and helium mass flow controller 13, respectively, to the reaction chamber 1 and 2 as necessary through gas lines 18 and 20, respectively, via a gas line 16. Further, RF power can be applied from the RF generator 14 to the reaction chamber 1 or 2 using a switch 15 via respective matching boxes (MB). The pressure in the reaction chambers 1 and 2 is controlled by the auto pressure controller 3.
Although FIG. 1 illustrates the apparatus comprising two bottles 7, 8, one RE generator 14, one auto pressure controller 3, one pump 4, and four gas lines 17, 18, 19, 20, the apparatus can further comprise one remote plasma unit. Also, the apparatus can further comprise one or more additional reaction chambers, one or more bottles, and two or more gas lines. The RF generator can be connected to each reaction chamber separately. For an apparatus for thermal cyclic processing, no RF generator is installed.
A skilled artisan will appreciate that the apparatus includes one or more controller(s) (not shown) programmed or otherwise configured to cause the deposition and reactor cleaning processes described elsewhere herein to be conducted. The controller(s) are communicated with the various power sources, heating systems, pumps, robotics, and gas flow controllers or valves of the reactor, as will be appreciated by the skilled artisan.
In the above, an area including the valves v7, v8, v9, and v10 constitutes a gas flow switching unit provided between the gas lines 9, 10 and the gas inlet lines 17, 19. By manipulating the valves v7 to v10 associated with the valves v1 to v6, which gas is supplied to which reaction chamber can be controlled, and also the order of the reaction chambers 1, 2 to which the gas is supplied can be controlled.
FIGS. 11 to 16 illustrate how the gas flow switching unit causes uneven flow between two reaction chambers according to an embodiment of the present invention. FIG. 11 is a schematic view of a dual-chamber PEALD apparatus to which an embodiment of the present invention is applied. In the figure, a two-dot chain line represents a portion equipped with a heating element for temperature control, and a broken line represents a portion covered with a heat-insulating material without a heating element. In this figure, the apparatus comprises a bottle unit 45 including a bottle (BLT 1) 43 containing a liquid material (e.g., a phosphorous dopant); a bottle unit 46 including a bottle (BLT 2) 44 containing a liquid material (e.g., a Si-containing precursor); a bottle-integrated gas system unit (Bottle IGS Unit) 47 for switching gas flow; a first reaction chamber (RC1) 41; a second reaction chamber (RC2) 42; an RF generator 50; and a remote plasma unit 49. A gas flows into the first reaction chamber 41 through a gas inlet line 51, whereas a gas flows into the second reaction chamber 42 through a gas inlet line 52, and a gas is discharged from a reaction space of each reaction chamber 41, 42 through an exhaust line 66 with a valve v40, and from a bottom of each reaction chamber 41, 42 through an exhaust line 65 with a valve v39. The exhaust line 65 is merged to the exhaust line 66, and then the gases are discharged through an auto pressure controller 48. A process gas is fed to the gas inlet line 51 through a gas line 62, and a process gas is fed to the gas inlet line 52 through a gas line 61. A gas is supplied to the remote plasma unit 49 through a line 67 and excited, and then fed to the gas inlet lines 51, 52 through valves v37 and v38, respectively. An additive gas, inert gas, etc. arc fed to the gas inlet lines 51, 52 through lines marked with broken lines. RF power is applied to each reaction chamber 41, 42 from the RF power generator 50. The integrated gas system 47 is a unit for switching gas flow, wherein a first carrier gas is fed to the integrated gas system 47 through a gas line 59, and a second carrier gas is fed to the integrated gas system 47 through a gas line 60. The first carrier gas flows out from the integrated gas system 47 to the bottle unit 45 through a gas line 55 with a pressure transducer 53, and a gas flows into the integrated gas system 47 from the bottle unit 45 through a gas line 56. The second carrier gas flows out from the integrated gas system 47 to the bottle unit 46 through a gas line 58 with a pressure transducer 54, and a gas flows into the integrated gas system 47 from the bottle unit 46 through a gas line 57. A process gas flows out from the integrated gas system 47 through the gas line 62 toward the first reaction chamber 41, whereas a process gas flows out from the integrated gas system 47 through the gas line 61 toward the second reaction chamber 42. A liquid material is supplied to the bottle 43 through a line 64, and another liquid material is supplied to the bottle 44 through a line 63. A skilled artisan will appreciate that the apparatus includes one or more controller(s) (not shown) programmed or otherwise configured to cause the deposition and reactor cleaning processes described elsewhere herein to be conducted. The controller(s) are communicated with the various power sources, heating systems, pumps, robotics, and gas flow controllers or valves of the reactor, as will be appreciated by the skilled artisan.
FIG. 12 illustrates step 1 of a process sequence in the dual-chamber PEALD apparatus illustrated in FIG. 11 according to an embodiment of the present invention. In step 1, the first carrier gas (represented by a thick solid line) flows into the integrated gas system 47 through the gas line 59 and flows out therefrom through the gas line 61 via a line 68 with a valve v26 and a line 71 with a valve v28 where a valve v24, a valve v25, and a valve v27 are closed. The first carrier gas is then fed as a purge gas to the second reaction chamber 42 through the gas inlet line 52. The second carrier gas (represented by a thick broken line) flows into the integrated gas system 47 through the gas line 60 and flows out therefrom via a valve v33 to the bottle unit 46 through the gas line 58 where a valve v31 is closed. The second carrier as enters the bottle 44 via a valve v35 and is discharged therefrom with a vaporized precursor (as a precursor represented by a thick dotted line with circular dots) through a gas line 57 via a valve v34 where a valve v36 is closed. The precursor flows into the integrated gas system 47 through the gas line 57 via a valve v32 and flows out therefrom through the gas line 62 via a line 69 and a line 70 with a valve v29 where a valve v30 is closed. The precursor is then fed to the first reaction chamber 41 through the gas inlet line 51.
FIG. 13 illustrates step 2 of a process sequence in the dual-chamber PEALD apparatus illustrated in FIG. 11 according to an embodiment of the present invention. In step 2, the valve v27 is open while the valve v28 is closed so that the first carrier gas is fed to the first reaction chamber 41 in place of the second reaction chamber 42 through the gas line 70, the gas line 62, and the gas inlet line 51. Also, the valve v30 is open while the valve v29 is closed so that the precursor is fed to the second reaction chamber 42 in place of the first reaction chamber 41 through the gas line 71, the gas line 61, and the gas inlet line 52.
FIG. 14 illustrates step 3 of a process sequence in the dual-chamber PEALD apparatus illustrated in FIG. 11 according to an embodiment of the present invention, in step 3, the valve v26 is closed while the valve v24 is open so that the first carrier gas flows out from the integrated gas system 47 via the valve v24 to the bottle unit 45 through the gas line 55. The first carrier gas enters the bottle 43 via a valve v21 and is discharged therefrom with a vaporized dopant (as a dopant represented by a thick dotted line with square dots) through the gas line 56 via a valve v22 where a valve v23 is closed. The dopant flows into the integrated gas system 47 through the gas line 56 via a valve v2.5 and flows out therefrom through the gas line 62 via the line 68 and the line 70 with the valve v27 where the valve v28 is closed. The dopant is then fed to the first reaction chamber 41 through the gas inlet line 51, in place of the second reaction chamber 42. Also, the valve v31 is open while the valve v33 is closed so that the second carrier gas is fed to the second reaction chamber 42 through the gas line 69, the gas line 71 with the valve v30, the gas line 61, and the gas inlet line 52.
FIG. 15 illustrates step 4 of a process sequence in the dual-chamber PEALD apparatus illustrated in FIG. 11 according to an embodiment of the present invention. In step 4, the valve v27 is closed while the valve v28 is open so that the dopant is fed to the second chamber 42 in place of the first reaction chamber 41 through the gas line 71, the gas line 61, and the gas inlet line 52. Also, the valve v30 is closed while the valve v29 is open so that the second carrier gas is fed as a purge gas to the first reaction chamber 41 in place of the second reaction chamber 42 through the gas line 70 the gas line 62, and the gas inlet line 51.
Step 5 is substantially the same as step 3 illustrated in FIG. 14 so that the dopant is fed to the first reaction chamber 41, whereas the purge gas is fed to the second reaction chamber 42.
Step 6 is substantially the same as step 4 illustrated in FIG. 15 so that the dopant is fed to the second reaction chamber 42, whereas the purge gas is fed to the first reaction chamber 41.
FIG. 16 illustrates step 7 of a process sequence in the dual-chamber PEALD apparatus illustrated in FIG. 11 according to an embodiment of the present invention. In step 6, the valve v26 is open while the valve v24 is closed so that the first carrier gas is fed as a purge gas to the second reaction chamber 42 through the gas line 68, the gas line 71, and the gas line 61, and the gas inlet line 52.
In the above, the dopant gas has a higher vapor pressure than the precursor, and thus, it is more difficult to purge the dopant from the reaction chamber than to purge the precursor. In step 3 (FIG. 14), the dopant is fed to the first reaction chamber 41, and in step 4 (FIG. 15), the purge has is fed to the first reaction chamber 41. That is, the gas fed to the first reaction chamber 41 is changed from the dopant to the purge gas. Since the dopant is fed to the first reaction chamber 41 by using the first carrier gas, whereas the purge gas is the second carrier gas, the above change (changing from the dopant to the purge gas at the first reaction chamber) is accomplished by switching the used carrier gas from the first carrier has to the second carrier gas, i.e., when the dopant is fed to the first reaction chamber 41, a first half of the gas line 70 with the valve v27 is used (FIG. 14), while when the purge gas is fed to the first reaction chamber 41, a second half of the has line 70 with the valve v29 is used (FIG. 15), and thus, the different parts of the has line 70 is used.
In contrast, in step 6 (FIG. 15), the dopant is fed to the second reaction chamber 42, and in step 7 (FIG. 16), the purge gas is fed to the second reaction chamber 42. That is, the gas fed to the second reaction chamber 42 is changed from the dopant to the purge gas. Since the dopant is fed to the second reaction chamber 42 by using the first carrier gas, whereas the purge gas is also the first carrier gas, the above change (changing from the dopant to the purge gas at the second reaction chamber) is accomplished by switching the gas flow pass from the one passing through the bottle 43 to the one bypassing the bottle 43 using the same first carrier gas, i.e., when the dopant is fed to the second reaction chamber 42, a first half of the gas line 71 with the valve v28 is used (FIG. 15), and also when the prune gas is fed to the second reaction chamber 42, the first half of the gas line 71 with the valve v28 is used (FIG. 16), and thus, the same part of the gas line 71 is used. For the reason above, when the second reaction chamber 42 is purged after the dopant is fed, the purge gas carries some residual dopant left in the gas line 71 to the second reaction chamber 42. This occurs only in the second reaction chamber (when the feeding order is changed, the above problem occurs only in the first reaction chamber). As a result, deviations of film properties occur between the first and second reaction chambers.
In some embodiments, by changing the order of the reaction chambers to which the gas is fed, the above problem can effectively be resolved.
FIG. 2 illustrates a schematic process sequence applied to a dual-chamber PEALD apparatus according to a comparative embodiment. A, B, and C represent process A (e.g., gas supply), process B (e.g., gas supply), and process C (e.g., RF application), respectively. In this sequence, a cycle constituted by A, A, B, C, B, and C starts always from the reaction chamber 1 (RC1), followed by the reaction chamber 2 (RC2). Thus, the above discussed problem, deviations of film properties between the reaction chambers, occurs. FIG. 3 illustrates a schematic process sequence applied to a dual-chamber PEALD apparatus according to a comparative embodiment. In this sequence, the cycle starts always from the second reaction chamber, followed by the first reaction chamber, and thus, the same problem occurs.
FIG. 4 illustrates a schematic process sequence applied to a dual-chamber PEALD apparatus according to another embodiment of the present invention. A blank square other than A, B, or C represents purging without specific treatment, in this sequence, the first time, the cycle starts from the first reaction chamber, but the second time, the cycle starts from the second reaction chamber, i.e., the order of the reaction chambers at which the cycle starts first is changed per cycle. That is, the cycle starts alternately at the first and second reaction chambers. By starting the cycle alternately at the first and second reaction chambers, the problem of reactor-to-reactor deviation can effectively be resolved.
FIG. 5 illustrates a schematic process sequence applied to a dual-chamber PEALD apparatus according to still another embodiment of the present invention. In this sequence, process A is started always from the first reaction chamber, but process B and C start alternately from the second and first reaction chambers. By starting only a part of the cycle alternately at the first and second reaction chambers, the problem of reactor-to-reactor deviation can effectively be resolved.
FIG. 6 illustrates a schematic process sequence applied to a dual-chamber PEALD apparatus according to yet another embodiment of the present invention. In this sequence, process C is conducted simultaneously at the first and second reaction chambers, and process A is started alternately from the first and second reaction chambers, and process B is also started alternately from the first and second reaction chambers, but independently of process A. By starting parts of the cycle alternately and independently at the first and second reaction chambers (also starting a part of the cycle simultaneously at the first and second reaction chambers), the problem of reactor-to-reactor deviation can effectively be resolved.
FIG. 7 illustrates a schematic process sequence applied to a triple-chamber PEALD apparatus according to a comparative embodiment. A, B, C, and D represent process A (e.g., gas supply), process B (e.g., gas supply), process C gas supply), and process D (e.g., RF application), respectively. In this sequence, a cycle constituted by A, A, B, D, C, B, D, and C starts always from the reaction chamber 1 (RC1), followed by the reaction chamber 2 (RC2) and the reaction chamber 3 (RC3). Thus, the above discussed problem, deviations of film properties among the reaction chambers, occurs. FIG. 8 illustrates a schematic process sequence applied to a triple-chamber PEALD apparatus according to an embodiment of the present invention. In this sequence, the first time, the cycle starts from the first reaction chamber, but the second time, the cycle starts from the third reaction chamber, i.e., the order of the reaction chambers at which the cycle starts first is changed per cycle. That is, the cycle starts alternately at the first and third reaction chambers. By starting the cycle alternately at the first and third reaction chambers, the problem of reactor-to-reactor deviation can effectively be resolved.
FIG. 9 illustrates a detailed process sequence applied to a dual-chamber PEALD apparatus according to a comparative embodiment. This detailed sequence corresponds to the schematic sequence illustrated in FIG. 2. In this sequence, blank (no number) represents purge without switching valves; “1” represents purge with switching valves (0.1 sec); “2” represents supply of SiO precursor (0.3 sec); “3” represents purge of SiO precursor (0.9 sec); “4” represents supply of P (phosphorous) dopant (0.3 sec); “5” represents purge of P dopant (0.1 sec); and “6” represents application of RF power (0.2 sec). In this sequence, in the first reaction chamber (the upper sequence), after process 4 (supply of P dopant), the purging (process 5) starts using the same carrier gas, and thus, some residual dopant may be introduced into the first reaction chamber. However, the purging using the same carrier gas lasts only for 0.4 seconds, and thereafter, the carrier gas is switched to a different carrier gas which does not contain residual dopant. In contrast, in the second reaction chamber (the lower sequence), after process 4 (second occurrence), the purging (process 5) starts using the same carrier gas, and lasts for 1.0 seconds because no carrier gas switching is conducted during the above process 5. Thus, more residual dopant may be introduced into the second reaction chamber than in the first reaction chamber, causing reactor-to-reactor deviations.
FIG. 10 illustrates a detailed process sequence applied to a dual-chamber PEALD apparatus according to an embodiment of the present invention. This detailed sequence corresponds to the schematic sequence illustrated in FIG. 4. In this sequence, the cycle starts alternately from the first and second reaction chambers, and thus, the above problem can effectively be resolved.
In some embodiments, the gas supply system disclosed in U.S. patent application publication No. 2014/0033978 can be used, the disclosure of which is incorporated herein by reference in its entirety.
In some embodiments, because variations of film properties among reaction chambers can be controlled by changing the order of the reaction chambers in which at least one step in one cycle is conducted, by checking parameters indicative of variations of film properties downstream of the reaction chambers and feeding hack the parameters to a control unit, the suitable order can be determined and the processing can be performed using the determined order, thereby improving uniformity of processing in all the reaction chambers. The above feedback control can be performed continuously. For example, SPOES (Self Plasma OES, product name, sold by Manoteck Inc., South Korea) or a self plasma monitoring sensor installed downstream of a reaction chamber can be used for the above purpose.
EXAMPLE 1
A phosphorous silicon glass (PSG) film was formed on a substrate (Φ300 mm) by PEALD under the conditions shown in FIG. 19 using the PEALD apparatus illustrated in FIG. 1. The sequence of cycles of PEALD was that shown in FIG. 9 (Comparative Example) and in FIG. 10 (Example 1). As a precursor, bisdiethylaminosilane (BDEAS) was used, and as a dopant, trimethylphosphite (TMPI) was used, wherein the vapor pressure of the dopant was about 3.5 times higher than that of the precursor.
FIG. 17 is a graph showing a phosphorous concentration of the phosphorus silicon glass (PSG) film in a depth direction which was deposited in each reaction chamber according to the Comparative Example, STD RC1 and STD RC2 represent the first reaction chamber and the second reaction chamber in the Comparative Example. FIG. 18 is a graph showing a phosphorous concentration of the phosphorus silicon glass (PSG) film in a depth direction which was deposited in each reaction chamber according to Example 1. ALT RC1 and ALT RC2 represent the first reaction chamber and the second reaction chamber in Example 1. As can be seen from these figures, when the cycle was started alternately from the first and second reaction chambers in Example 1, no significant deviation in the concentration of dopant in the film between the first and second reaction chambers was detected (see c and d), whereas when the cycle was started always from the first reaction chamber, significant deviations in the concentration of dopant in the film between the first and second reaction chambers were detected (see a and b).
It will be understood by those of skill in the art that numerous and various modifications can be made without departing from the spirit of the present invention. Therefore, it should be clearly understood that the forms of the present invention are illustrative only and are not intended to limit the scope of the present invention.

## Claims

1. A method for performing uniform processing in multiple reaction chambers sharing a first gas source and a second gas source, each reaction chamber having a gas inlet line through which a first gas from the first gas source, a second gas from the second gas source, and a purge gas are introduced into the reaction chamber, wherein a same target treatment is conducted on a first substrate in a first reaction chamber and on a second substrate in a second reaction chamber, separately, said target treatment being cyclic processing constituted by predetermined times of cycles, wherein one cycle is considered to be complete when one cycle of the target treatment is conducted on the first substrate and the second substrate one time at the respective reaction chambers wherein the one cycle starts at one of the reaction chambers and then starts at another of the reaction chambers before the one cycle ends at the one of the reaction chambers, said complete cycle comprising:
(i) supplying the first gas to the multiple reaction chambers through the respective gas inlet lines in a first supply order where the first gas is supplied to the first reaction chamber and then to the second reaction chamber or in a second supply order where the first gas is supplied to the second reaction chamber and then to the first reaction chamber; and
(ii) supplying the second gas to the multiple reaction chambers through the respective gas inlet lines in a supply order where the second gas is supplied to one of the multiple reaction chambers and to another of the multiple reaction chambers;
wherein the purge gas is supplied to the multiple reaction chambers through the respective gas inlet lines after every supply of the first gas and after every supply of the second gas so as to purge the first gas and the second gas, respectively, from the multiple reaction chambers and the gas inlet lines, wherein steps (i) and (ii) are conducted in a same order in each cycle in each reaction chamber,
wherein the complete cycle is continuously repeated until the predetermined times of cycles of the target treatment are performed in the multiple reaction chambers, wherein the supply order of the first gas is changed between the first supply order and the second supply order every time the complete cycle is repeated.

2. The method according to claim 1, wherein the supply order of the second gas is changed per cycle while the supply order of the first gas is unchanged.

3. The method according to claim 1, wherein the supply order of each of the first gas and the second gas is changed per cycle.

4. The method according to claim 1, wherein one cycle is comprised of steps (i) to (iii), and step (ii) is repeated in the cycle wherein the supply order of the second gas is changed when step (ii) is repeated in the cycle, said cycle being repeated in step (iv).

5. The method according to claim 1, further comprising (iiia) applying RF power in the multiple reaction chambers after every step (iii).

6. The method according to claim 5, wherein RF power is applied to the multiple reaction chambers sequentially or simultaneously.

7. The method according to claim 5, wherein the multiple reaction chambers share an RF generator which generates RF power.

8. The method according to claim 5, wherein the target treatment is deposition of a film by plasma-enhanced atomic layer deposition (PEALD).

9. The method according to claim 1, wherein a supply rate of the first gas is two or more times higher than a supply rate of the second gas.

10. The method according to claim 1, wherein the first gas source and the second gas source include bottles storing liquid compounds, respectively, vaporized gases of which are the first gas and the second gas, respectively.

11. The method according to claim 10, wherein a first gas line from the first gas source is ramified and connected to each of the gas inlet lines of the multiple reaction chambers, and a second gas line from the second gas source is ramified and connected to each of the gas inlet lines of the multiple reaction chambers, wherein the first gas and the purge gas are introduced to the multiple reaction chambers through the first gas line, the lines ramified therefrom, and the gas inlet lines of the multiple reaction chambers, while the second gas and the purge gas are introduced to the multiple reaction chambers through the second gas line, the lines ramified therefrom, and the gas inlet lines of the multiple reaction chambers, wherein each ramified line is provided with a valve, and the gas flows defined in steps (i) to (iii) are controlled using each valve.

12. The method according to claim 11, wherein the purge gas continuously flows alone or with the first gas through the first gas line, while the purge gas continuously flows alone or with the second gas through the second gas line.

13. The method according to claim 1, wherein the multiple reaction chambers are two reaction chambers.

14. The method according to claim 1, wherein the multiple reaction chambers share an exhaust system, and the pressure of each reaction chamber is controlled using the exhaust system.

15. The method according to claim 1, wherein the multiple reaction chambers each comprise another gas line, through which an additive gas or inert gas is supplied to the multiple reaction chambers.