WO2008059827A1 - Procédé de dopage de plasma - Google Patents
Procédé de dopage de plasma Download PDFInfo
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- WO2008059827A1 WO2008059827A1 PCT/JP2007/071996 JP2007071996W WO2008059827A1 WO 2008059827 A1 WO2008059827 A1 WO 2008059827A1 JP 2007071996 W JP2007071996 W JP 2007071996W WO 2008059827 A1 WO2008059827 A1 WO 2008059827A1
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- substrate
- plasma doping
- plasma
- dose
- doping method
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/22—Diffusion of impurity materials, e.g. doping materials, electrode materials, into or out of a semiconductor body, or between semiconductor regions; Interactions between two or more impurities; Redistribution of impurities
- H01L21/223—Diffusion of impurity materials, e.g. doping materials, electrode materials, into or out of a semiconductor body, or between semiconductor regions; Interactions between two or more impurities; Redistribution of impurities using diffusion into or out of a solid from or into a gaseous phase
- H01L21/2236—Diffusion of impurity materials, e.g. doping materials, electrode materials, into or out of a semiconductor body, or between semiconductor regions; Interactions between two or more impurities; Redistribution of impurities using diffusion into or out of a solid from or into a gaseous phase from or into a plasma phase
Definitions
- the present invention relates to a plasma doping method, and more particularly to a plasma doping method for introducing impurities into the surface of a solid sample such as a semiconductor substrate.
- a plasma doping (PD) method is known in which impurities are ionized and introduced into a solid sample with low energy (see, for example, Patent Document 1). .
- the plasma doping method is described as an item in Non-Patent Document 1, and is also described in Non-Patent Document 2 as a next-generation impurity introduction technique that replaces the ion implantation method!
- an ion source that generates a plasma from a gas
- an analysis magnet that performs mass separation to select only desired ions from ions extracted from the ion source, and accelerates the desired ions
- An apparatus configuration having an electrode and a process chamber for injecting desired accelerated ions into a silicon substrate is used.
- the energy for extracting ions from the ion source and the acceleration energy should be reduced. If the extraction force is reduced, the number of ions extracted will decrease. Furthermore, when the acceleration energy decreases, the beam diameter increases due to the repulsive force caused by the charge between ions while the ion beam is transported from the ion source to the wafer.
- the throughput of the injection process is reduced.
- the throughput starts to decrease when the acceleration energy is 2 keV or less, and when the acceleration energy is 0.5 keV or less, the beam transport itself becomes difficult.
- B is implanted to a depth of about 20 nm. In other words, when trying to form a thinner tension zone, productivity will be drastically reduced. There is a problem.
- a cylindrical vacuum vessel capable of disposing a silicon substrate inside, a plasma generation source for inducing plasma, a bias electrode on which the silicon substrate is mounted, A device configuration having a bias power source for adjusting the potential of the first electrode is used. That is, in the plasma doping method, an apparatus configuration completely different from ion implantation that does not have an analysis magnet and an acceleration electrode is used. Specifically, a bias electrode that also serves as a wafer holder is installed in a vacuum container, and ions in the plasma are accelerated and introduced into the wafer by the potential generated between the plasma and the wafer.
- the low energy plasma can be used directly to introduce the impurities, so that the wafer can be irradiated with a larger amount of low energy ions than ion implantation.
- the dose rate by plasma doping is an order of magnitude greater than that of ion implantation, this feature makes it possible to maintain high throughput even with low energy B implantation.
- Non-patent Document 3 a process technique for forming an extremely shallow and low-resistance extension region by applying a plasma doping method
- a method has been proposed in which 26 6 is diluted as much as possible to increase safety, while stable generation and maintenance of plasma and easy control of dopant implantation without lowering doping efficiency are proposed.
- Patent Document 2 B H gas as a substance containing impurities to be doped is diluted with He gas having a low ionization energy.
- B H is discharged after the He plasma is generated in advance.
- Patent Document 3 A plasma doping method is proposed (Patent Document 3). Specifically, in Patent Document 3, for example, when a silicon substrate is irradiated with a BH / He plasma and biased, A method for controlling the dose by discovering that there is a time zone in which the dose amount of the gas is almost constant and making the process window a time zone in which the dose amount is almost constant without depending on this time change. Disclosure!
- Patent Document 1 US Patent No. 4912065
- Patent Document 2 Japanese Patent Application Laid-Open No. 2004-179592
- Patent Document 3 International Publication No. 06/064772 Pamphlet
- Patent 1 International Technology Roadmap ⁇ semiconductors 2001 bdition (I TRS2001) (especially Shallow Junction Ion Doping in Figure 30 of Front End Process)
- Non-Patent Document 3 Y. Sasaki et al., B2 H6 Plasma Doping with "In-situ He Pre-amorphizati on", Symp. On VLSI Tech., 2004, p.180
- control of the dose amount is a very important issue.
- the uniformity of the dose amount in the substrate surface is an extremely important issue in the formation of elements.
- the present invention provides a plasma doping method capable of controlling the dose amount with high accuracy, and in particular, a plasma doping method capable of controlling the uniformity of the dose amount in the substrate surface with high accuracy.
- the purpose is to provide.
- a plasma doping method is a plasma in which an impurity region is formed on a surface of a substrate by exposing the substrate to a plasma made of a gas containing impurities in a vacuum vessel.
- a doping method, introduced into the substrate As for the dose amount of the impurity, the dose amount of one of the central portion and the peripheral portion of the substrate becomes larger than the dose amount of the other in the initial stage of doping, and then the other dose amount of the other is
- the plasma doping condition is set so as to be larger than the dose, and plasma doping of the impurity is performed on the substrate.
- the inventors of the present application have found that the dose amount in the center of the wafer is higher than the dose amount at the peripheral edge of the wafer in the initial stage of doping.
- the plasma doping conditions are set so that the rate of increase of the dose at the wafer peripheral portion increases with time, compared to the rate of increase of the dose at the center of the wafer.
- the dose distribution curve shape slope
- the rate of change of the dose amount was decreasing.
- the present invention pays attention to the fact that the distribution becomes uniform and the change rate of the dose becomes small near the time when the slope of the in-plane distribution of the dose is reversed.
- the end of the plasma doping time is set in the vicinity of the time when the slope of the substrate in-plane distribution is reversed.
- the dose amount at the central portion of the substrate is the dose amount at the peripheral portion of the substrate at the initial stage of doping. Then, the plasma doping condition is set so that the dose amount of the peripheral edge of the substrate becomes larger than the dose amount of the central portion of the substrate, and the plasma doping condition is set with respect to the substrate. Fi plasma impurity doping may be used.
- the central portion of the substrate is set under the set plasma doping conditions.
- a time range in which the dose amounts of the peripheral portions are substantially equal is detected in advance, and a plasma of the impurity is applied to the substrate using a predetermined plasma doping time included in the time range. Doping It is a further feature.
- the plasma doping condition is that, in the initial stage of the doping, the impurity dose distribution in the main surface of the substrate is centered on the substrate. It may be set to be rotationally symmetric as a reference. According to this configuration, it is possible to realize a more uniform dose distribution within the wafer surface.
- the plasma doping condition is that the impurity dose distribution in the main surface of the substrate in the initial stage of doping is centered on the substrate. It may be set to have a slope on at least one diameter that passes through. According to this configuration, it is possible to achieve a more uniform dose distribution in the wafer plane.
- the plasma doping conditions may be changed while the impurity is plasma-doped to the substrate.
- the changed plasma doping condition may be set such that the amount of change per unit time of the dose amount in the central portion and the peripheral portion of the substrate is different.
- the plasma doping condition in the initial stage of the doping is, for example,
- the flow rate distribution is set to be larger in the central portion of the substrate than the peripheral portion of the substrate, and the changed plasma doping condition is the gas flow rate distribution in the substrate. You may set so that it may become small in the said center part of the said board
- the flow rate distribution of the B H / He gas is higher than the substrate periphery.
- the plasma doping time is set within a predetermined time range including the time at which the dose profile is reversed, the plasma doping time is set at each point on the substrate surface. Since the dose amount integrated with respect to is almost the same even if the time slightly deviates, it is possible to stably perform plasma doping with excellent uniformity of the dose amount in the substrate surface.
- conditions are set so that the dose at the center of the substrate is larger than the dose at the periphery of the substrate, and then the dose per unit time is set.
- the conditions so that the increase is smaller at the center of the substrate than at the periphery of the substrate, it is possible to obtain a dose distribution excellent in in-plane uniformity of the substrate.
- the plasma doping conditions are changed during the plasma doping of the impurities on the substrate!
- the plasma doping condition in the initial stage of doping is set so that the concentration distribution of the gas is larger in the central portion of the substrate than in the peripheral portion of the substrate.
- the changed plasma doping condition may be set so that the concentration distribution of the gas is smaller in the central portion of the substrate than in the peripheral portion of the substrate.
- the plasma doping condition in the initial stage of doping may be a distribution of a source node for generating the plasma in the central portion of the substrate as compared with the peripheral portion of the substrate.
- the plasma doping condition that is set to be smaller and the changed plasma doping condition may be set so that the source power distribution is larger in the central portion of the substrate than in the peripheral portion of the substrate.
- the plasma doping condition in the initial stage of the doping is set so that the temperature distribution of the substrate is low at the peripheral portion of the substrate and high at the central portion of the substrate.
- the plasma doping condition may be set such that the temperature distribution of the substrate is high at the peripheral portion of the substrate and low at the central portion of the substrate.
- plasma doping treatment is performed using BH as a doping source gas.
- boron-based film As it goes on, a film containing boron (boron-based film) is deposited on the inner wall of the vacuum vessel. As the deposition thickness of this boron-based film increases, the probability of boron-based radical adsorption on the inner wall of the vacuum vessel decreases, so the density of boron-based radicals in the plasma will increase. It has been.
- the power of the dose introduced into the substrate to be processed by the plasma doping process after being repeatedly performed on the processing substrate is only about 8 to 30%.
- the plasma doping process is repeated for more substrates to be processed, and when the area where the boron-based film is formed on the inner wall of the vacuum vessel exceeds a certain size, the area where the boron-based film is formed is It becomes difficult to increase.
- the rate of increase in dose with the increase in the number of substrates subjected to plasma doping treatment also decreases.
- the boron dose caused by particles containing boron supplied into the plasma by sputtering when ions in the plasma collide with the boron-based film deposited on the inner wall of the vacuum vessel is less than the total dose. And become dominant.
- the amount of boron supplied into the plasma by sputtering from the boron-based film is small at the initial stage of doping (the processing time is up to about 5 seconds). It increases when the time is long (about 20 seconds).
- the cause of this is that as the processing time increases, the temperature of the inner wall of the vacuum vessel rises due to the heating by the plasma, so that after a certain amount of processing time has elapsed compared to the initial stage of driving, the boron is sputtered from the boron film. This is thought to be easier. Further, boron supplied from this boron-based film into the plasma is more likely to be doped at the wafer peripheral portion than at the wafer central portion. This is because the distance to the boron-based film on the inner wall of the vacuum vessel is shorter at the wafer periphery than at the wafer center.
- the amount of boron doped into the substrate from the plasma, excluding the polrons caused by the boron-based film is approximately the same at the beginning of doping, but after a certain amount of processing time has passed, It can be seen that the peripheral dose is greater than the central dose.
- the present inventors have conducted various experiments. As a result, as the doping treatment time increases, particles containing boron are supplied into the plasma from the inner wall of the vacuum vessel. Thus, the dose tends to increase at the peripheral edge of the wafer, and this has been found to be one of the reasons why the uniformity of the dose in the substrate surface cannot be obtained.
- the inventors of the present application when a boron-based film is formed on the inner wall of the vacuum vessel, in the initial stage of doping, the dose amount at the wafer central portion is the dose amount at the wafer peripheral portion. If the condition is set to be larger than that, then there will be a time when the dose profile is reversed due to the supply of particles containing boron from the inner wall of the vacuum vessel into the plasma.
- a predetermined time range including a plasma doping time process window to achieve a high uniformity in the in-plane dose of the substrate and forming an impurity region, the inventors have come up with the invention.
- a film containing the impurity is already formed on the inner wall of the vacuum vessel before the plasma doping of the impurity with respect to the substrate.
- the plasma doping condition may be set so that the peripheral portion of the substrate and the central portion of the substrate are the same with respect to the gas flow rate distribution.
- a film containing the impurity is already formed on the inner wall of the vacuum vessel, and the plasma doping condition is that the concentration distribution of the gas is The peripheral edge portion of the substrate and the central portion of the substrate may be set to be the same.
- a film containing the impurity is already formed on the inner wall of the vacuum vessel, and the plasma doping condition is to generate the plasma.
- the source power distribution may be set to be the same at the peripheral portion of the substrate and the central portion of the substrate.
- a film containing the impurity is already formed on the inner wall of the vacuum vessel, and the plasma doping condition is determined by the temperature distribution of the substrate.
- the peripheral edge portion of the substrate and the central portion of the substrate may be set to be the same.
- the uniformity of the sheet resistance (Rs) after annealing in the substrate surface that is, the uniformity of the dose amount in the substrate surface
- the plasma doping method according to the present invention is based on such knowledge.
- the dose amount increases very slowly as the doping processing time increases, so by setting the plasma doping time within the range of the process window including the time in which the inversion occurs, There is also an effect that the dose amount can be easily controlled with high accuracy.
- the dose amount of the other of the central portion and the peripheral portion of the substrate is the above-described dose amount.
- the plasma doping condition may be changed after the dose becomes larger than one dose.
- the plasma doping condition is changed several times during the plasma doping of the impurity with respect to the substrate! You may be fi.
- the gas may contain molecules B H (where m and n are natural numbers) composed of boron atoms and hydrogen atoms.
- the gas includes B H and He.
- 26 degrees is preferably 0.01% by mass or more and 1% by mass or less.
- the gas may be BF 4, AsH or
- 3 4 may contain any of PH.
- the substrate may be a silicon substrate.
- the process window is set by setting the vicinity of the time at which the dose distribution in the substrate surface is reversed as the end point of the plasma doping time.
- the dose amount can be controlled with high accuracy, and the impurity region that is controlled with high accuracy can be formed stably and uniformly in the substrate surface. It becomes.
- FIG. 1 is a diagram showing an example of setting plasma doping conditions in the plasma doping method according to the first embodiment of the present invention.
- FIG. 2 is a cross-sectional view showing a configuration example of a plasma doping apparatus used for performing the plasma doping method according to the first embodiment of the present invention.
- FIG. 3 is a flowchart of the plasma doping method according to the first embodiment of the present invention. 4] FIG. 4 is a view showing a change over time of the dose amount in the substrate plane in the plasma doping method according to the first embodiment of the present invention.
- FIG. 5 is a diagram showing the change over time of the sheet resistance in the substrate plane in the plasma doping method according to the first embodiment of the present invention.
- FIG. 6 is a diagram showing a setting example of plasma doping conditions in the plasma doping method according to the second embodiment of the present invention.
- FIG. 7 is a view showing a change over time of the dose amount in the substrate surface in the plasma doping method according to the second embodiment of the present invention.
- FIG. 8 is a diagram showing the time change of the sheet resistance in the substrate plane in the plasma doping method according to the second embodiment of the present invention.
- FIG. 9 is a cross-sectional view showing a configuration example of a plasma doping apparatus used for carrying out the plasma doping method according to the third embodiment of the present invention.
- FIG. 10 is an enlarged cross-sectional view of a gas supply port that is a main part of the plasma doping apparatus shown in FIG.
- FIG. 11 is a diagram showing the time change of the sheet resistance in the substrate plane in the plasma doping method according to the fourth embodiment of the present invention.
- FIGS. 12 (a) to 12 (! Are diagrams showing the time change of the sheet resistance in the substrate plane in the plasma doping method according to the fourth embodiment of the present invention.
- FIG. 13 is a diagram showing the relationship between the number of processed substrates and the sheet resistance in the plasma doping method according to the fourth embodiment of the present invention.
- FIG. 14 is a graph showing the relationship between plasma doping time and sheet resistance in the plasma doping method according to the fourth embodiment of the present invention.
- FIG. 15 is a diagram showing the relationship between plasma doping time and sheet resistance uniformity in the substrate plane in the plasma doping method according to the fourth embodiment of the present invention.
- FIG. 16 is a diagram showing the relationship between the plasma doping time, the average value of sheet resistance, and the in-plane uniformity in the plasma doping method according to the fourth embodiment of the present invention. Explanation of symbols
- the magnitude is reduced by utilizing the reversal phenomenon of the relative magnitude relationship between the dose at the center of the substrate and the dose at the peripheral edge of the substrate as the doping process time elapses.
- the time when the relationship is reversed that is, the time at which the dose at the center of the substrate is equal to the dose at the edge of the substrate is used as the process window of the plasma doping time.
- one dose amount in the central portion and the peripheral portion of the substrate is the other dose amount.
- plasma doping conditions are set so that the other dose amount becomes larger than the one dose amount, and the substrate is subjected to impurity plasma doping.
- the plasma doping conditions are set so that the impurity dose distribution in the main surface of the substrate is rotationally symmetric with respect to the center of the substrate at the initial stage of doping.
- the substrate in-plane distribution of the dose is inclined by a predetermined inclination at the initial stage of doping. And a time range in which the dose amount of the impurity introduced into the silicon substrate is substantially uniform in the substrate surface under the plasma doping conditions in which the slope of the distribution is set to be reversed thereafter. Then, the silicon substrate is doped with impurities using a predetermined plasma doping time included in the time range. As a result, it is possible to stably form an impurity region in which the impurity concentration is controlled with high accuracy and in-plane uniformity.
- the flow distribution of the gas (plasma generating gas) in the substrate surface is large at the center of the substrate and small at the periphery of the substrate. That is, the plasma doping conditions are set so as to have a predetermined inclination. Subsequently, after a certain amount of doping processing time has elapsed, as shown by the curve a2 in FIG. 1, the gas flow distribution in the substrate surface is small at the center of the substrate and large at the periphery of the substrate. Change the plasma doping conditions. Thereby, the increase amount of the dose amount per unit time can be made smaller at the substrate center portion than at the substrate peripheral portion.
- the impurities introduced into the substrate are activated and become carriers.
- the dose amount can be calculated by activating the impurities introduced in this way by annealing and measuring the sheet resistance in the substrate due to the activated impurities.
- annealing is performed with a large amount of heat, all of the impurities introduced into the substrate are activated and become carriers, so the sheet resistance S decreases. That is, the sheet resistance and the dose amount are in an inversely proportional relationship.
- the condition of the annealing performed before the sheet resistance measurement is 1075 ° C for 20 seconds. Under these annealing conditions at a high temperature for a relatively long time, it can be assumed that the impurities are almost completely electrically activated.Therefore, there is a one-to-one correspondence between the sheet resistance and the dose. Can be read as the dose distribution.
- the sheet resistance measurement was performed at 121 locations on the substrate surface excluding the end portion (width 3mm) of the 300mm diameter substrate (wafer). That is, the sheet resistance described later is an average value of sheet resistance measured at 121 locations unless otherwise specified.
- the in-plane uniformity of sheet resistance was determined using the standard deviation of sheet resistance measured at 121 locations.
- FIG. 2 is a cross-sectional view showing a configuration example of a plasma doping apparatus used for performing the plasma doping method of the present embodiment.
- the plasma doping apparatus shown in FIG. 2 is provided with a vacuum vessel 1, a vacuum vessel 1 and A sample stage 6 on which a substrate 9 to be processed is placed, a first gas supply device 2 and a second gas supply device 15 for supplying gas into the vacuum vessel 1, and an exhaust device for exhausting the inside of the vacuum vessel 1.
- the main components are a molecular pump 3 as a power source, a pressure regulating valve 4 as a pressure control device for controlling the pressure in the vacuum vessel 1, and a high-frequency power source 5 and a coil 8 for generating plasma in the vacuum vessel 1.
- the vacuum chamber 1 is evacuated through the exhaust port 11.
- a cylindrical liner (inner chamber 1) 21 is disposed in the vacuum vessel 1, and this prevents gas disturbance in the vacuum vessel 1 caused by the extraction port of the substrate 9 to be processed.
- the gas distribution in the vacuum vessel 1 can be made concentric.
- the cylindrical liner 21 may be provided with an outlet 22 for the substrate 9 to be processed.
- the first groove 13 and the first groove respectively provided in the dielectric window 7 serving as the ceiling part of the vacuum vessel 1 are provided.
- the gas supply port 14, the second groove 17 and the second gas supply port 18 provide two systems of gas supply. That is, the gas flow rate can be controlled independently for each system.
- first gas supply device 2 supplies gas to the first groove 13 through the pipe 12 and the through hole 19 in the inner wall of the vacuum vessel 1.
- the second gas supply device 15 supplies gas to the second groove 17 through the pipe 16 and the through hole 20 in the inner wall of the vacuum vessel 1.
- both the first gas supply device 2 and the second gas supply device 15 are configured to supply a mixed gas (BH / He gas) of BH and He. , B
- a pressure regulating valve is introduced while a predetermined gas is introduced into the vacuum vessel 1 from the gas supply apparatuses 2 and 15 and exhausted by the turbo molecular pump 3 as an exhaust apparatus. 4 can keep the inside of the vacuum vessel 1 at a predetermined pressure.
- a high frequency power of 13.56 MHz, for example, to the coil 8 provided in the vicinity of the dielectric window 7 facing the sample stage 6 by the high frequency power source 5
- an inductively coupled plasma is generated in the vacuum vessel 1.
- a silicon substrate 9 is placed on the sample stage 6 as the substrate 9 to be processed.
- high-frequency power is supplied to the sample stage 6 outside the vacuum vessel 1.
- the high frequency power supply 10 functions as a voltage source that controls the potential of the sample stage 6 so that the substrate 9 to be processed has a negative potential with respect to plasma.
- the high frequency power source 10 is configured to supply voltage to the sample stage 6 via a matching unit (not shown).
- the gas supplied from the gas supply devices 2 and 15 into the vacuum vessel 1 is exhausted from the exhaust port 11 by the turbo molecular pump 3.
- the turbo molecular pump 3 and the exhaust port 11 are arranged below the sample stage 6.
- the pressure regulating valve 4 is a lift valve located below the sample stage 6 and directly above the turbo molecular pump 3.
- the sample stage 6 is fixed to the vacuum vessel 1 by, for example, four support columns (not shown).
- FIG. 3 is a flowchart showing a typical processing procedure of the plasma doping method of the present embodiment using the plasma doping apparatus shown in FIG.
- step 1001 the distribution of the dose amount of the impurity introduced into the substrate 9 to be processed at the initial stage of doping has a predetermined inclination in the plane of the substrate 9 to be processed, and thereafter the inclination of the distribution.
- Plasma doping conditions are set so that inversion occurs.
- step 1002 a time range in which the dose amount of the impurity introduced into the substrate 9 to be processed is substantially uniform in the substrate plane under the plasma doping conditions set in step 1001 is determined.
- plasma doping of impurities is performed on the substrate 9 to be processed using a predetermined plasma doping time included in the time range determined in Step 1003.
- the B H gas diluted to about 2% by mass with He
- the B H concentration / He concentration is 0.05% by mass / 99.95% by mass.
- Each is supplied into the vacuum vessel 1.
- the gas supply devices 2 and 15 are each provided with a mass flow controller (not shown), whereby the BH / He mixed gas is supplied from the gas outlets 14 and 18 at individually controlled flow rates. . And figure
- a mixed gas is injected from the gas outlet 18 corresponding to the center of the substrate 9 to be processed at a flow rate of, for example, 540 cc / min (standard state) and the substrate 9 About the flow distribution of the mixed gas sprayed on the substrate 9 to be processed by setting so that the mixed gas is injected from the gas outlet 14 corresponding to the peripheral portion at a flow rate of, for example, 180 cc / min (standard state). Obtain the distribution shown in the curve al in Fig. 1 with the force S.
- the gas flow distribution as shown by the curve a2 in FIG. 1 is such that the mixed gas is injected from the gas blowing port 18 at a flow rate of, for example, 180 cc / min (standard state) and the gas blowing port 14 It is obtained by setting the gas mixture to be injected at a flow rate of 540cc / min (standard condition).
- the plasma doping is performed so that the gas flow rate distribution in the substrate surface is large in the central portion of the substrate and small in the peripheral portion of the substrate.
- the plasma doping conditions are changed so that the gas flow distribution in the substrate surface is small at the center of the substrate and large at the periphery of the substrate.
- the pressure, source power (power applied by the high-frequency power source 5) and bias power (power applied by the high-frequency power source 10) in the vacuum container 1 are not changed during the doping process, and are maintained at constant values.
- the pressure in the vacuum vessel 1 is 0.9 Pa
- the source power is 2000 W
- the bias power is 135 W.
- FIG. 4 is a diagram showing the change over time of the dose amount in the substrate surface when the plasma doping conditions are set as described above.
- the dose shown in FIG. 4 is obtained by converting the value of sheet resistance shown in FIG. 5 described later.
- the gas flow rate setting is changed between the processing time tl and the processing time t2 (t2> tl) as shown by the curve a2 in FIG. this
- the increase in dose per unit time is smaller in the center of the substrate than in the periphery of the substrate.
- FIG. 5 is a diagram showing the change over time of the sheet resistance in the substrate plane. As shown in Fig. 4 and Fig. 5, the in-plane uniformity is extremely good near the processing time (t3, t4) in which profile inversion occurs in both dose and sheet resistance, and the profile is obtained. Being done! /, The power of being S component.
- a more uniform dose distribution within the wafer surface can be formed with high throughput.
- a uniform dose amount in the wafer plane is obtained by changing the flow rate of the gas supplied from the first gas supply device 2 and the second gas supply device 15 during plasma doping. Although a distribution was obtained, the same effect can be obtained by changing other parameters as described below.
- the gas concentration described above is selected, and the gas concentration distribution in the substrate surface may be adjusted as shown by the curves al and a2 in FIG. 1 according to the doping processing time. good.
- a method for obtaining a gas concentration distribution as shown by a curve al using the plasma doping apparatus shown in FIG. 2 as the gas concentration on the vertical axis in FIG. 1 will be described.
- Each of the gas supply devices 2 and 15 in the plasma doping apparatus shown in FIG. 2 is a bonnet filled with BH gas diluted to about 2% by mass with He, for example.
- the dilution rate is set separately for each gas supply device. Specifically, for example, the B H concentration / He concentration is adjusted to 0.01 mass% / 99.99 mass% from the gas outlet 14.
- Gas is supplied.
- the gas outlet 18 for example, BH concentration / He
- a mixed gas whose concentration is adjusted to 0.05% by mass / 99.95% by mass is supplied.
- the gas supply devices 2 and 15 are each provided with a mass flow controller (not shown), whereby a BH / He mixed gas is supplied from the gas outlets 14 and 18 at the same flow rate of, for example, 300 cc / min. So that As a result, the vertical
- a gas concentration distribution as shown by the curve al when the axis is the gas concentration can be realized.
- the gas concentration distribution as shown by the curve a2 with the vertical axis in FIG. 1 as the gas concentration is, for example, BH concentration / He concentration from the gas outlet 18 to 0.01 mass% / 99.99 mass%. Adjust to
- the mixed gas is injected and, for example, B H concentration / He concentration is
- the source power or the substrate temperature may be adjusted during plasma doping.
- an apparatus having two coils that is, a coil disposed above the central portion of the substrate and a coil disposed above the peripheral portion of the substrate is used.
- the initial stage of doping processing time tl
- the source power of the coil disposed above the central portion of the substrate is reduced and the source power of the coil disposed above the peripheral portion of the substrate is increased.
- the source partition of the coil disposed above the central portion of the substrate is increased and the peripheral edge of the substrate is increased. Reduce the source power of the coil placed above.
- the source power for example, set it to about 2200W
- the source power set it to about 1000W.
- sputtering becomes dominant in the balance between sputtering and doping, so that the dose is reduced.
- doping becomes dominant, and the dose is increased. Therefore, as the processing time increases to t2, t3, t4, and t5 (t5>t4>t3> t2), the dose at the central portion of the substrate becomes smaller than the dose at the peripheral portion of the substrate. That is, inversion of the dose profile occurs.
- the entire upper surface of the sample stage 6 can be cooled by a refrigerant such as ethylene glycol, and the sample stage 6
- a refrigerant such as ethylene glycol
- the sample stage 6 One heater is provided at each of the central part and the peripheral part.
- the coolant is cooled to 10 ° C.
- the heating temperature by the heater at the center of the sample stage 6 is set to 90 ° C.
- the heating temperature by the heater at the peripheral edge of the sample stage 6 is set.
- Set to 50 ° C. the temperature of the central portion of the substrate 9 to be processed can be set to 70 ° C.
- the temperature of the peripheral portion of the substrate 9 to be processed can be set to 30 ° C.
- the heating temperature by each heater may be reversed.
- the temperature at the center of the substrate and the temperature at the peripheral edge of the substrate can be set separately.
- the heating temperature by the heater at the center of the sample table 6 is increased and the heating temperature by the heater at the peripheral portion of the sample table 6 is decreased.
- the heating temperature by the heater at the center of the sample stage 6 is set to 90 ° C
- the heating temperature by the heater at the periphery of the sample stage 6 is set to 50 ° C.
- the obtained substrate temperature distribution that is, the substrate temperature distribution shown in the curve al when the vertical axis is the substrate temperature in FIG. 1, can be obtained.
- the heating temperature by the heater at the center of the sample stage 6 is set to 50 ° C
- the heating temperature by the heater at the peripheral part of the sample stage 6 is set to 90 ° C.
- the substrate temperature distribution in which the temperature at the center of the substrate is set to 30 ° C and the temperature at the periphery of the substrate is set to 70 ° C, that is, the curve a2 when the vertical axis is the substrate temperature in FIG.
- the substrate temperature is higher! /, And the substrate temperature is lower, and the amount of gas constituent particles and radicals adsorbed to the substrate is larger than in the case of plasma doping. Therefore, V is higher in the substrate surface, and the temperature of the part is lower! / And the dose is higher than that of the part.
- the heating temperature by the heater at the center of the sample stage 6 is increased and the heating temperature by the heater at the peripheral edge of the sample stage 6 is decreased.
- the impurity in the main surface of the substrate in the initial stage of doping The plasma doping conditions were set so that the distribution of the dose amount of the object was rotationally symmetric with respect to the center of the substrate.
- the plasma doping conditions are set so that the impurity dose distribution in the main surface of the substrate has an inclination on at least one diameter passing through the center of the substrate in the initial stage of doping. Then, the plasma doping conditions are changed so that the slope in the distribution is reversed.
- FIG. 6 shows a setting example of plasma doping conditions in the plasma doping method according to the present embodiment. That is, at the initial stage of doping, as shown by the straight line al in FIG. 6, the flow rate distribution of the gas (plasma generating gas) in the substrate surface is the right end of the substrate (the right end of at least one diameter passing through the center of the substrate: The plasma doping conditions are set so as to be large at the left end of the substrate (the left end of at least one diameter passing through the center of the substrate: the same applies below), that is, to have a predetermined inclination. Subsequently, after a certain amount of doping processing time has elapsed, as shown by the straight line a2 in FIG.
- the plasma doping is performed so that the gas flow distribution in the substrate surface is small at the right end of the substrate and large at the left end of the substrate. Change the conditions.
- gas concentration, source power, or substrate temperature may be used instead of the gas flow rate, as in the first embodiment.
- FIG. 7 is a diagram showing the change over time of the dose amount in the substrate surface when the plasma doping conditions are set as described above.
- processing time tl the dose at the right end of the substrate is larger than the dose at the left end of the substrate.
- the gas flow rate setting is changed between the processing time tl and the processing time t2 (t2> tl) as shown by the straight line a2 in FIG.
- the amount of increase in dose per unit time is smaller at the right end of the substrate than at the left end of the substrate.
- the uniformity in the substrate surface is very good in the vicinity of the processing time (t3, t4) in which profile inversion occurs in both dose and sheet resistance, and a profile is obtained. / !, the power of S, the power of S.
- the dose distribution is reduced.
- the timing when the slope reverses, and the timing is stable for a relatively long time. That is, when plasma doping is started, the dose is initially increased greatly. Thereafter, the increase in dose becomes extremely small with the lapse of processing time.
- the dose amount can be accurately controlled by such a time period in which the increase in dose amount is extremely small, that is, by the inclination of the dose amount distribution.
- the substrate diameter direction distribution of the dose amount has a predetermined inclination at the initial stage of doping, and then the inclination of the distribution is inverted.
- a time range in which the dose of impurities introduced into the substrate to be processed is substantially uniform in the substrate diameter direction is detected in advance, and a predetermined plasma doping included in the time range is detected.
- FIG. 9 is a cross-sectional view showing a configuration example of a plasma doping apparatus used for carrying out the plasma doping method of the present embodiment
- FIG. 10 is a main part of the plasma doping apparatus shown in FIG. It is an expanded sectional view of the gas supply port which is.
- the same components as those in the plasma doping apparatus shown in FIG. 2 described in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
- the basic configuration of the plasma doping apparatus shown in FIGS. 9 and 10 is the same as that shown in FIG. Although it is the same as that of one bing apparatus, there are the following differences. That is, in the plasma doping apparatus shown in FIGS. 9 and 10, only the first gas supply apparatus 2 is provided as a single gas supply apparatus, and the first gas supply apparatus 2 is evacuated through the pipe 12. Connected to a gas supply port 23 for supplying gas into the vacuum vessel 1 from almost the center of the upper surface of the vessel 1. Further, instead of the cylindrical liner (inner chamber) 21 of the plasma doping apparatus shown in FIG. 2, a cylindrical liner (inner chamber) 24 is provided so as to surround the periphery of the sample stage 6 on which the substrate 9 to be processed is placed.
- a plurality of liner exhaust ports 25 are provided on the lower surface of the cylindrical liner 24 in a rotationally symmetrical manner with respect to the sample stage 6.
- the plasma doping apparatus shown in FIGS. 9 and 10 differs from the plasma doping apparatus shown in FIG. 2 in the arrangement of the sample stage 6, the turbo molecular pump 3, the pressure regulating valve 4, the exhaust port 11, and the like. Yes.
- a gas supply port 23 which is a feature of the plasma doping apparatus shown in FIGS. 9 and 10, has an on-axis injection supply port 26 and an off-axis injection that penetrate the dielectric window 7 provided on the upper surface of the vacuum vessel 1, respectively. It has a supply port 27.
- the pipe 12 includes a first gas supply line 32 connected to the on-axis injection supply port 26 and a second gas supply line 33 connected to the off-axis injection supply port 27, and the gas supply line 32 and Each 33 is provided with a flow controller 30 and 31 individually. This allows gas to be injected independently from the on-axis injection supply port 26 and off-axis injection supply port 27 while controlling the flow rate and concentration.
- both gas supply lines 32 and 33 are configured to supply B H / He gas.
- the amount may be adjusted and supplied, or the same flow rate of B H / He gas may be supplied.
- the impurity dose distribution in the main surface of the substrate is set to be rotationally symmetric with respect to the substrate center as in the first embodiment.
- a large number of off-axis injection supply ports 27 are arranged at predetermined intervals on the peripheral edge of the nozzle of the gas supply port 23.
- the off-axis injection supply port 27 are arranged in the diameter direction at the nozzle of the gas supply port 23.
- a force capable of independently injecting gas from each of the on-axis injection supply port 26 and the off-axis injection supply port 27 while controlling the flow rate thereof is supplied to the central portion of the substrate 9 to be processed, and the gas injected from the off-axis injection supply port 27 is supplied to the peripheral portion of the substrate 9 to be processed. That is, the on-axis injection supply port 26 of the plasma doping apparatus shown in FIGS. 9 and 10 corresponds to the gas outlet 18 of the plasma doping apparatus shown in FIG. 2, and is off-axis of the plasma doping apparatus shown in FIGS.
- the injection supply port 27 corresponds to the gas blowing port 14 of the plasma doping apparatus shown in FIG. Therefore, the plasma doping apparatus shown in FIGS. 9 and 10 can be applied not only to the present embodiment but also to the first and second embodiments described above and the fourth embodiment described later. is there.
- FIG. 11 and FIGS. 12 (a) to (! Are diagrams showing the time variation of the sheet resistance in the substrate plane when the plasma doping method of the present embodiment is used.
- FIG. 11 shows the relationship between the distance from the center of the substrate and the sheet resistance at each processing time.
- FIGS. 12 (a) to 12 (h) will be described in detail later.
- the relative dose between the dose at the center of the substrate and the dose at the peripheral edge of the substrate as the doping process time elapses.
- the time for which the magnitude relationship is reversed that is, the time at which the dose at the center of the substrate is equal to the dose at the periphery of the substrate is the plasma doping time. It is used as a process window.
- this embodiment is different from the first embodiment in order to realize the technical feature described above, that is, the magnitude relationship between the dose amount at the center of the substrate and the dose amount at the peripheral edge of the substrate.
- a method of changing doping conditions (parameters) during plasma doping is used, whereas in this embodiment, boron or the like formed on the inner wall surface of the vacuum vessel is used. Utilizes the properties of a film containing impurities (hereinafter also referred to as a boron-based film).
- the distribution of gas (plasma generating gas) flow rate, gas concentration, substrate temperature, source power, etc. is determined at each position on the substrate. Are set to be as equal as possible to keep the values of these parameters constant during plasma doping. Therefore, normally, by setting such parameters, the relative magnitude relationship between the dose at the center of the substrate and the dose at the periphery of the substrate is reversed during plasma doping, in other words, the substrate center. The dose at the substrate and the dose at the peripheral edge of the substrate are not balanced.
- the force S is used to cause the above-described reversal phenomenon by utilizing the properties of the boron-based film as described below.
- the boron-based film for example, has a B H concentration / He concentration of 0.05% by mass in a vacuum vessel.
- FIG. 13 shows the plasma doping apparatus shown in FIG. 2, in which the pressure inside the vacuum chamber is 0.9 Pa, the source power is 2000 W, the BH concentration / He concentration is 0.05 mass% / 99.95 mass%, BH / He gas. Flow rate is 30
- the dose by plasma doping after the boron-based film is formed is about nine times the dose by plasma doping immediately after maintenance.
- the effect that doping using the boron-based film as a boron source becomes a dominant factor with respect to the total dose, and at the same time, discharge (plasma doping treatment) )), It is possible to obtain a constant and stable dose.
- the force capable of using the plasma doping apparatus as shown in FIG. 2 requires attention to the configuration of the cylindrical liner 21.
- the cylindrical liner 21 is disposed rotationally symmetrically with respect to the center of the substrate on a plane including the surface of the substrate 9 to be processed. That is, it is desirable that the intersection of the inner wall of the cylindrical liner 21 and the plane including the surface of the substrate 9 to be processed is a circle, and the circle is a perfect circle.
- the opening 22 when the cylindrical liner 21 is provided with an opening 22 for transporting the substrate 9 to be processed, the opening 22 includes the inner wall of the cylindrical liner 21 and the surface of the substrate 9 to be processed. Do not place it on the circle created by the intersection with the plane.
- a lid that closes the opening 22 may be provided.
- the opening 22 when the substrate 9 to be processed is transported, the opening 22 is positioned on the circle, but after the substrate 9 is transferred, the sample stage 6 is moved vertically upward together with the substrate 9 to be processed. During the dope, the opening 22 may be positioned vertically below the circle! /. By doing so, it is possible to form a boron-based film with rotational symmetry with respect to the center of the substrate.
- the process window of the plasma doping time in the plasma doping method of the present embodiment will be described. As described above, this process window is arranged so that the circle formed by the intersection of the inner wall of the cylindrical liner 21 and the plane including the surface of the substrate 9 to be processed is rotationally symmetric with respect to the center of the substrate.
- plasma (B H / He) composed of a mixed gas of B H and He (B H / He gas).
- FIG. 14 shows a plasma doping apparatus shown in FIG. 2 having a vacuum container on which a boron-based film is deposited.
- the BH concentration / He concentration is 0.05 mass% / 99.95 mass%, and the vacuum container
- the plasma consisting of B H / He gas is used under the condition of 26 cc flow rate of 300cc / min (standard condition).
- the boron dose using the boron-based film attached to the inner wall of the vacuum vessel (cylindrical liner 21 in the plasma doping apparatus shown in Fig. 2) as the boron source is increased noticeably.
- the dose amount by the plasma doping process after forming the boron-based film is about nine times the dose amount by the plasma doping process immediately after the maintenance. Accordingly, as the processing time elapses, the amount of increase in dose per unit time at the peripheral edge of the substrate becomes larger than that in the central portion of the substrate.
- FIG. 12 (a) shows a balance between the dose at the peripheral edge of the substrate and the dose at the central portion of the substrate from the beginning of doping until some processing time elapses. The process is shown.
- Figures 12 (c), (d), (e) and (f) show the processes before and after the inversion of the slope of the dose distribution.
- Figures 12 (d) and (e) Board edge
- the balance between the dose amount and the dose amount at the center of the substrate is maintained! /.
- FIGS. 12 (f), (g), and (h) the inclination of the dose distribution is inverted, and the dose at the peripheral edge of the substrate is larger than the dose at the center of the substrate. It shows the process.
- FIGS. 12 (a) to (! Show the in-plane distribution of the sheet resistance obtained by annealing after the plasma doping.
- the boron concentration was measured using SIMS (secondary ion mass spectrometry) without annealing for the sample immediately after the rasmadbing (sample equivalent to the substrate to be measured in Fig. 12 ⁇ to (h)). analyzed. According to the results, for all samples equivalent to the substrates to be measured in Figs. 12 (a) to (!), The depth at which the boron concentration is 1 X 10 18 cm 3 is 9 nm to l lnm. there were. The dose is 4.2 X 10 14 cm- 2 for the sample equivalent to the substrate to be measured in Fig.
- FIG. 12 (a) which is equivalent to the substrate to be measured in Fig. 12 (b). In the sample, it is 8.7 X 10 14 cm- 2 , and in the sample equivalent to the substrate to be measured in Fig. 12 (c), it is 1.2 X 10 15 cm- 2 , and the measurement in Fig. 12 (d) a substrate and the same sample 1. 5 X 10 15 cm- 2 of interest, a diagram 12 1. 6 X 10 15 cm- 2 at the measurement subject to substrate equivalent sample (e), FIG. It is 2.0 X 10 15 cm-2 for the sample equivalent to the substrate to be measured in 12 (f), and 2.3 X 10 15 cm for the sample equivalent to the substrate to be measured in Fig. 12 (g). — 2 and 2.6 ⁇ 10 15 cm ⁇ 2 for the sample equivalent to the substrate to be measured in Fig. 12 (h).
- FIG. 15 is a diagram showing the relationship between the plasma doping time and the in-plane uniformity of sheet resistance in the plasma doping method of the present embodiment.
- the plasma doping time process window is near the time (in the range from 60 to 200 seconds corresponding to Figs. 12 (c) to (f)) where the inversion of the slope of the dose distribution occurs.
- the processing time corresponding to FIGS. 12 (d) and 12 (e) is from 90 to 120 seconds).
- a substrate uniformity of 1.4% can be obtained at 1 ⁇ .
- the sheet resistance of 1.36% uniformity at 1 ⁇ can be obtained.
- force S In general, the smaller the value of 1 ⁇ , the better the technique for improving uniformity.
- the technical difficulty increases dramatically.
- the use of the present invention can easily obtain the in-plane uniformity of 1.4% or less of the sheet resistance, which shows the effectiveness of the present invention.
- the plasma doping time means the time during which the bias is applied while irradiating the substrate with plasma.
- Fig. 12 (a) it is 5 seconds
- Fig. 12 (b) it is 20 seconds
- Fig. 12 (c) it is 60 seconds
- Fig. 12 (d) it is less than 90 seconds
- Fig. 12 (e) it is less than 12 (f) (200 or less
- FIG. 12 (a) Show the plasma doping time.
- Fig. 12 (a) it is 5 seconds
- Fig. 12 (b) it is 20 seconds
- Fig. 12 (c) it is 60 seconds
- Fig. 12 (d) it is less than 90 seconds
- Fig. 12 (e) it is less than 12 (f) (200 or less
- Fig. 12 (g) 400 or less
- FIGS. 12 (a) to (!) FIG. 15 (curve E1) and FIG. It can be rotationally symmetric with respect to the center of the substrate.
- a plasma driving time of 20 seconds to 200 seconds can achieve in-plane uniformity of 2.7% or less, and a plasma doping time of 90 seconds to 120 seconds enables a substrate surface of 1.42% or less.
- Internal uniformity can be achieved.
- the slope of the in-plane distribution of the dose is counter to the change in processing time. In the vicinity of the rolling time, it is possible to obtain a dose distribution with good uniformity within the substrate surface over a predetermined time. This is because if the dose amount changes with the lapse of processing time, the dose amount in the substrate is relatively small so far,
- the dose amount has been relatively large so far, and after the dose amount of the other part has caught up and the difference has decreased, the former dose amount has overtaken the latter dose amount.
- the time span is almost twice as long. In addition, it is possible to obtain a dose distribution with good uniformity in the substrate surface.
- the sheet resistance uniformity in the substrate surface can be stably improved.
- the plasma doping method of the present embodiment capable of achieving this is a very effective means for ensuring the sheet resistance, that is, the dose uniformity within the substrate surface in plasma doping.
- the plasma doping method of the present embodiment can achieve high-precision control of the dose amount while ensuring the uniformity of the dose amount in the substrate surface.
- the parameter setting may be changed after the force S described for the method of using boron sputtering and after the inversion of the slope of the dose distribution occurs or in the vicinity of the time at which the inversion occurs.
- the parameter setting may be changed once or a plurality of times after the inversion of the slope of the dose distribution occurs or in the vicinity of the time at which the inversion occurs. .
- the application range of the present invention is the process. Only some of the various noirations regarding the configuration, shape, and arrangement of the laser doping apparatus are illustrated. That is, it goes without saying that various variations other than those exemplified in the respective embodiments can be considered in applying the present invention.
- the force S exemplifies the case where the sample (substrate to be processed) is a semiconductor substrate made of silicon, and also when processing samples made of various other materials,
- the present invention can be applied.
- the present invention is also effective when the substrate to be processed is a strained silicon substrate or an SOI (semiconductor on insulator) substrate. The reason is that these substrates have the same structure as that of the silicon substrate at the surface exposed to the plasma.
- the present invention is particularly effective when the impurity is polone, arsenic, phosphorus, aluminum, or antimony. The reason is that these impurities can form a shallow junction in the transistor formation region.
- the introduced impurity is boron
- the force S using B H gas is not limited to this, and the distribution of boron atoms and hydrogen atoms is not limited thereto.
- a gas containing a child B H (where m and n are natural numbers) or BF may be used. Introducing impure m n
- the object is arsenic
- a gas containing AsH may be used, or the introduced impurity may be used.
- a gas containing PH may be used.
- the present invention described in the first to fourth embodiments is effective when the concentration of the gas containing impurities is low, and in particular, a plasma that requires high-precision control of the dose amount. It is effective as a doping method.
- the gas supplied into the vacuum vessel is a gas containing a doping material
- the present invention is effective even when the supplied gas does not include a doping raw material and the doping raw material is generated from solid impurities. That is, the present invention is also effective when a solid containing impurity atoms is placed in a reaction vessel and plasma doping is performed by converting the impurity atoms into plasma using a plasma made of He or the like.
- the plasma doping method of the present invention can achieve the in-plane uniformity of the dose amount.
- the plasma doping method of the present invention is useful not only for the impurity introduction step of semiconductors but also for applications such as the production of thin film transistors used in the liquid crystal field.
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JP2010519735A (ja) * | 2007-02-16 | 2010-06-03 | ヴァリアン セミコンダクター イクイップメント アソシエイツ インコーポレイテッド | 改良型ドーズ量制御付きマルチステップ・プラズマドーピング方法 |
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WO2008041702A1 (fr) * | 2006-10-03 | 2008-04-10 | Panasonic Corporation | Procédé et appareil de dopage de plasma |
TW200932081A (en) * | 2008-01-11 | 2009-07-16 | Murata Manufacturing Co | Multilayer ceramic substrate, method for manufacturing multilayer ceramic substrate and method for suppressing warpage of multilayer ceramic substrate |
US20120302049A1 (en) * | 2011-05-24 | 2012-11-29 | Nanya Technology Corporation | Method for implanting wafer |
WO2014165669A2 (en) * | 2013-04-04 | 2014-10-09 | Tokyo Electron Limited | Pulsed gas plasma doping method and apparatus |
US9336990B2 (en) * | 2013-08-29 | 2016-05-10 | Varian Semiconductor Equipment Associates, Inc. | Semiconductor process pumping arrangements |
CN109478494B (zh) * | 2016-06-03 | 2023-07-18 | 应用材料公司 | 扩散腔室内部的气流的设计 |
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JP2018195806A (ja) * | 2017-04-24 | 2018-12-06 | インフィネオン テクノロジーズ アクチエンゲゼルシャフトInfineon Technologies AG | 半導体ウェハの中性子照射ドーピングのための装置および方法 |
US10468148B2 (en) | 2017-04-24 | 2019-11-05 | Infineon Technologies Ag | Apparatus and method for neutron transmutation doping of semiconductor wafers |
US11250966B2 (en) | 2017-04-24 | 2022-02-15 | Infineon Technologies Ag | Apparatus and method for neutron transmutation doping of semiconductor wafers |
Also Published As
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JPWO2008059827A1 (ja) | 2010-03-04 |
JP5237820B2 (ja) | 2013-07-17 |
US7790586B2 (en) | 2010-09-07 |
US20090233427A1 (en) | 2009-09-17 |
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