Source: http://patents.com/us-9818600.html
Timestamp: 2017-11-24 23:53:13
Document Index: 219290460

Matched Legal Cases: ['Application No. 2014', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16']

US Patent # 9,818,600. Substrate processing apparatus and method of manufacturing semiconductor device - Patents.com
United States Patent 9,818,600
Sato; Takayuki (Toyama, JP)
Family ID: 1000002948444
15/266,081
US 20170004966 A1 Jan 5, 2017
PCT/JP2015/056976 Mar 10, 2015
Mar 21, 2014 [JP] 2014-059307
Current CPC Class: H01L 21/02164 (20130101); H01J 37/32064 (20130101); H01J 37/32091 (20130101); H01L 21/02274 (20130101); H01J 37/32568 (20130101); H01J 37/32743 (20130101); H01J 37/32183 (20130101)
Current International Class: H01L 21/02 (20060101); H01J 37/32 (20060101)
Field of Search: ;438/788
2004/0025791 February 2004 Chen
07-086251 Mar 1995 JP
2009-231248 Oct 2009 JP
2013-055165 Mar 2013 JP
Primary Examiner: Armand; Mark
This application is a continuation of International Application No. PCT/JP2015/056976, filed Mar. 10, 2015, which claims priority under 35 U.S.C. .sctn.119 to Japanese Patent Application No. 2014-059307, filed Mar. 21, 2014, the entire contents of which are hereby incorporated by reference.
1. A substrate processing apparatus comprising: a plasma generating unit configured to excite a process gas into plasma state; a process chamber where a substrate is processed using the process gas excited in plasma state; a loading port installed at a sidewall of the process chamber, wherein the substrate is passed through the loading port when the substrate is loaded into the process chamber; a substrate support supporting the substrate in the process chamber; an electrode unit installed in the substrate support and including a plurality of divided electrodes; a plurality of impedance adjusting units configured to adjust impedances of the plurality of divided electrodes, wherein each of the plurality of impedance units is electrically connected to each of the plurality of divided electrodes; and a control unit configured to control the impedances of the plurality of impedance adjusting units so as to adjust the electrical potentials of the respective electrodes of the electrode unit, wherein the control unit controls the plurality of impedance adjusting units such that an electrical potential of an electrode positioned in a direction facing the loading port as viewed from the center of the electrode unit among the plurality of divided electrodes is higher than electrical potentials of the other electrodes among the plurality of divided electrodes such that an amount of active species of the excited process gas drawn toward the substrate is uniform throughout the surface of the substrate.
5. A substrate processing apparatus comprising: a plasma generating unit configured to excite a process gas into plasma state; a process chamber where a substrate is processed using the process gas excited in plasma state; a loading port installed at a sidewall of the process chamber, wherein the substrate is passed through the loading port when the substrate is loaded into the process chamber; a substrate support supporting the substrate in the process chamber; an electrode unit installed in the substrate support and including a plurality of divided electrodes; and an impedance adjusting unit electrically connected to each of the plurality of electrodes and configured to adjust an impedance thereof; wherein an electrode positioned in the center of the electrode unit among the plurality of electrodes comprises an extension part extending horizontally toward the loading port.
7. A method of manufacturing a semiconductor device, comprising: (a) loading a substrate into a process chamber of a substrate processing apparatus through a loading port; (b) placing the substrate on a substrate support having an electrode unit comprising a plurality of divided electrodes after performing (a); (c) electrically connecting each of a plurality of impedance adjusting units configured to adjust impedances of the plurality of divided electrodes to each of the plurality of divided electrodes; (d) configuring a control unit to control the impedances of the plurality of impedance adjusting units so as to adjust the electrical potentials of the respective electrodes of the electrode unit; (e) adjusting, via the control unit, an electrical potential applied to an electrode positioned in a direction facing the loading port as viewed from the center of the electrode unit among the plurality of divided electrodes to be higher than electrical potentials applied to the other electrodes among the plurality of divided electrodes state such that an amount of active species of an excited process gas drawn toward the substrate is uniform throughout the surface of the substrate; and (f) processing the substrate placed on the substrate support using the excited process gas in plasma state.
A process container 4 defining a process chamber includes a dome-shaped upper container 5 serving as a first container and a bowl-shaped lower container 6 serving as a second container. As the upper container 5 is disposed over the lower container 6, the process chamber 3 is formed. The upper container 5 is formed of a nonmetallic material such as aluminum oxide (Al.sub.2O.sub.3) or quartz (SiO.sub.2), and the lower container 6 is formed of a metallic material such as aluminum (Al).
The process chamber 3 has a susceptor 8 disposed in the center of the bottom portion thereof, the susceptor 8 serving as a substrate support for supporting the wafer 2. The wafer 2 is placed on a substrate placing surface 8a of the susceptor 8. The susceptor 8 may be formed of a nonmetallic material such as aluminum nitride (AlN), ceramics or quartz, in order to reduce metal contamination of the wafer 2. The susceptor 8 is electrically insulated from the lower container 6.
The susceptor 8 has a heater 9 buried therein, the heater 9 serving as a heating device and disposed parallel to the substrate placing surface 8a. The wafer 2 may be heated by the heater 9. As power is supplied to the heater 9, the surface of the wafer 2 is heated to a predetermined temperature (for example, between room temperature and 1,000.degree. C.). The susceptor 8 has a temperature sensor (not illustrated) installed therein, and the heater 9 and the temperature sensor are electrically connected to a controller 11 which will be described. The controller 11 is configured to control the power supplied to the heater 9 based on the temperature information detected by the temperature sensor.
As illustrated in FIG. 2, the susceptor 8 has a variable impedance electrode unit installed therein, the variable impedance electrode unit including two variable impedance electrodes for controlling the electrical potential of the wafer 2, or first and second variable impedance electrodes 15 and 16. The variable impedance electrodes 15 and 16 are disposed in parallel to the substrate placing surface 8a, and configured to uniformly adjust the electrical potential of the wafer 2.
The downstream end of a process gas supply pipe 28 for supplying a process gas including an oxygen containing gas such as oxygen (O.sub.2) gas and the downstream end of an inert gas supply pipe 29 for supplying an inert gas such as nitrogen (N.sub.2) gas are connected to join the upstream side of the gas supply pipe 27. The gas supply pipe 27, the process gas supply pipe 28 and the inert gas supply pipe 29 are formed of a nonmetallic material such as quartz or aluminum oxide and a metallic material such as SUS.
The process gas supply pipe 28 is sequentially connected to a process gas supply source 31, a mass flow controller (MFC) 32 serving as a flow rate controller, and a valve 33 serving as an opening/closing valve, from the upstream side to the downstream side of the process gas supply pipe 28. The inert gas supply pipe 29 is sequentially connected to an inert gas supply source 34, an MFC 35 serving as a flow rate controller, and a valve 36 serving as an opening/closing valve, from the upstream side to the downstream side of the inert gas supply pipe 29. The N.sub.2 gas which is an inert gas is used as a purge gas when a dilution gas of the process gas, a carrier gas of the process gas or a gas atmosphere is replaced.
The MFC 32 and the valve 33 are electrically connected to the controller 11. The controller 11 is configured to control the opening degree of the MFC 32 and the opening/closing of the valve 33 such that the flow rate of the process gas supplied into the process chamber 3 becomes a predetermined flow rate. As the valve 33 is opened/closed and the flow rate is controlled through the MFC 32, a desired amount of O.sub.2 gas serving as the process gas may be supplied into the process chamber 3 through the gas supply pipe 27, the buffer chamber 23 and the gas jetting port 25.
After O.sub.2 gas is supplied into the process chamber 3, magnetron discharge plasma is generated in the plasma generation area 43 of the process chamber 3 by the magnetic fields of the upper and lower magnets 47 and 48, along with forming an electric field by applying high-frequency power to the cylindrical electrode 44. At this time, the electric field and the magnetic field subject the released electron to orbital motion. The orbital motion raises the ionization generation rate of plasma, thereby generating high-density plasma.
When the wafer 2 is loaded into the process chamber 3, N.sub.2 gas serving as a purge gas may be supplied into the process chamber 3 from the gas supply unit while the process chamber 3 is exhausted by the exhaust unit. That is, the vacuum pump 42 may be operated and the valve 41 may be opened in order to exhaust the process chamber 3. Simultaneously, the valve 36 may be opened to supply N.sub.2 gas into the process chamber 3 through the buffer chamber 23. Thus, it is possible to suppress particles from permeating into the process chamber 3 or adhering to the surface of the wafer 2. The vacuum pump 42 is continuously operated until a substrate unloading step (STEP: 06) is ended after the substrate loading step (STEP: 01) is started.
Then, power is supplied to the heater 9 buried in the susceptor 8 in order to heat the surface of the wafer 2 to a predetermined temperature which ranges from 200.degree. C. to 750.degree. C. or desirably ranges from 350.degree. C. to 550.degree. C. At this time, the temperature of the heater 9 is adjusted by controlling the power supplied to the heater 9 based on temperature information detected by the temperature sensor (not illustrated).
When the surface of the wafer 2 is heated to a temperature of not less than 750.degree. C., diffusion of impurities may occur in a source region or drain region formed at the surface of the wafer 2, and the circuit characteristic may be degraded to reduce the performance of the semiconductor device. As the temperature of the wafer 2 is limited as described above, it is possible to suppress the diffusion of impurities in the source region or drain region formed at the surface of the wafer 2, the degradation of the circuit characteristic, and the reduction in performance of the semiconductor device.
Hereafter, an example in which O.sub.2 gas is used as a process gas will be described. First, the valve 33 is opened to supply O.sub.2 gas as the process gas into the process chamber 3 through the buffer chamber 23 from the process gas supply pipe 28. At this time, the opening degree of the MFC 32 is adjusted to set the flow rate of O.sub.2 gas to a predetermined flow rate.
When O.sub.2 gas is supplied as the process gas into the process chamber 3, N.sub.2 gas functioning as a carrier gas or dilution gas may also be supplied into the process chamber 3 from the inert gas supply pipe 29. That is, the valve 36 may be opened to supply N.sub.2 gas into the process chamber 3 through the buffer chamber 23 while the flow rate of N.sub.2 gas is adjusted through the MFC 35. Then, the supply of O.sub.2 gas into the process chamber 3 may be promoted.
After the supply of the process gas is started, predetermined high-frequency power is applied to the cylindrical electrode 44 through the matcher 45 from the high-frequency power supply 46, with the magnetic field being formed by the upper and lower magnets 47 and 48. The predetermined high-frequency power may range from 100 W to 1,000 W or desirably range from 100 W to 500 W. As a result, magnetron discharge occurs in the process chamber 3, and high-density plasma is generated in the plasma generation area 43 above the wafer 2. As the plasma is generated, the O.sub.2 gas supplied into the process chamber 3 is excited and activated. Then, active species such as active oxygen or oxygen radicals contained in the excited O.sub.2 gas are supplied to the wafer 2 such that oxidation is performed.
When the oxidation is ended, the supply of power to the cylindrical electrode 44 is stopped. Then, the valve 33 is closed to stop the supply of O.sub.2 gas into the process chamber 3. At this time, with the valve 41 open, the process chamber 3 is continuously exhausted through the gas exhaust pipe 38 so as to discharge a residual gas within the process chamber 3. Furthermore, as the valve 36 is opened to supply N.sub.2 gas as a purge gas into the process chamber 3, the discharge of the residual gas within the process chamber 3 may be promoted.
After the purge step STEP: 04 is completed, the opening degree of the APC 39 is adjusted to return the internal pressure of the process chamber 3 to the atmospheric pressure, while the temperature of the wafer 2 is lowered to a predetermined value which ranges from room temperature to 100.degree. C. Specifically, while N.sub.2 gas is supplied to the process chamber 3 with the valve 36 open, the opening degrees of the APC 39 and the valve 41 of the exhaust unit are controlled based on pressure information detected by a pressure sensor (not illustrated), and the internal pressure of the process chamber 3 is returned to the atmospheric pressure while the amount of power supplied to the heater 9 is controlled to lower the temperature of the wafer 2.
In the second embodiment, the diameter of the second variable impedance electrode 16 in a direction facing the loading/unloading port 10, e.g. the diameter of the second variable impedance electrode 16 including an extension part 16a is larger than the diameter of the second variable impedance which does not include the extension part 16a. That is, the second variable impedance electrode 16 has a shape which is extended a predetermined distance toward the loading/unloading port 10. Considering the circumferential direction, the variable impedance electrode 15 and the extension part 16a of the variable impedance electrode 16 are arranged in areas divided along the circumferential direction.
For example, when the diameter of the second variable impedance electrode 16 which does not include the extension part 16a facing the loading/unloading port 10 of the second variable impedance electrode 16 is 75 mm, the diameter of the second variable impedance electrode 16 including the extension part 16a may be set to 100 mm.
In the second embodiment, the extension part 16a is extended in the direction facing the loading/unloading port 10 from the portion close to the loading/unloading port 10 or specifically the central portion of the processed surface of the wafer 2.
Referring to FIGS. 7A and 7B, a first variable impedance electrode 56 is installed at the outer circumference of the second variable impedance electrode 16. The first variable impedance electrode 56 includes variable impedance electrodes divided by a predetermined angle to have a shape of an annulus sector. The first variable impedance electrode 56 includes three variable impedance electrodes divided by 120.degree., e.g. a first divided variable impedance electrode 57, a second divided variable impedance electrode 58 and a third divided variable impedance electrode 59.
The ECR-type plasma processing apparatus 68 includes a microwave introduction pipe 69 and a dielectric coil 71 which serve as a plasma generating unit for generating plasma by supplying a microwave. The microwave introduction pipe 69 is installed outside the ceiling of the process container 4, and the dielectric coil 71 is installed on an upper portion of an outer wall of the process container 4. In the ECR-type plasma processing apparatus 68, at least O.sub.2 gas serving as a process gas is supplied into the process chamber 3 through the gas introduction unit 22 from the gas supply pipe 27. While the process gas is supplied, a microwave 72 is introduced into the microwave introduction pipe 69 serving as the plasma generating unit, and then emitted into the process chamber 3. As the process gas is excited by the microwave 72 and the high-frequency power from the dielectric coil 71, active species may be generated.
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