TWI336484B - Cathode and counter-cathode arrangement in an ion source - Google Patents

Description

1336484 IX. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to an ion source suitable for use in an ion implanter comprising a cathode and a reverse cathode. [Prior Art]

The application of the invention lies in the ion implanter used in the manufacture of semiconductor components or other materials, but there are other possible applications. In the foregoing application, the semiconductor wafer is implanted into the wafer body by atomizing the atoms of the desired species to form regions of different conductivity. Examples of common dopants are boron, phosphorus, arsenic and antimony.

In general, the ion implanter includes an ion source within the vacuum of the vacuum processing chamber. The ion source can form ions using the plasma formed in the arc treatment chamber. The plasma ions are taken out of the arc processing chamber in an "ion shower" mode and moved to implant the plasma onto a target such as a semiconductor wafer. Alternatively, the extracted ions can be passed through a mass spectrometer to allow the desired mass of ions and energy to be selected and moved forward into the semiconductor wafer. A more detailed description of the ion implanter can be found in U.S. Patent No. 4,754,200. In a typical Bernas-type ion source, the hot electrons are emitted and accelerated under the influence of the electric field of the cathode, and are forced by the magnetic field to move toward the reverse cathode along the spiral path, and form an interaction between the arc treatment chamber and the precursor gas. Want to plasma. In a known configuration, the reverse cathode is connected to the cathode to have both 5 1336484

The common potential (refer to U.S. Patent Nos. 5,517,077 and 5,977,552, the negative cathode is a negative bias, such that it repels electrons from the cathode, increasing the number of helical paths of the ion source, thereby increasing the effect in the arc processing chamber. In the known configuration, the reverse cathode is electrically isolated to float close to the plasma potential (see U.S. Patent No. 5,703,372). The mass spectrometer of the ion implanter operates to select the desired mass of ions in a controlled magnetic field mode. (by its momentum or mass versus charge state) and exclude unwanted ions (ie somewhere different paths in the magnetic field). For example, in the case of boron doping, BF 3 is usually used as the precursor. Freeing in the processing chamber causes the plasma to contain approximately B+, F+, and BF2+ ions. This ionic mixture is extracted and subjected to mass analysis to ensure that only the desired B/BFX species are sent to the semiconductor wafer. Plant species need to implant B + ions, but there are other uses of BF2 + because BF2 + ions are free when implanting semiconductor wafers, and the boron produced can be lower. The present invention aims to increase the flexibility of ion source operation, such as the ion source most used for implanting different species (derived from common source materials). Optimizing the output of a particular ionic species (from a particular gas feed). In a first aspect of the invention, the invention relates to a method for displacing ions by ionization, > + Taiwan, many children. An atomic doping, or an ion source of a sub-cloth 6 1336484 implanter, comprising at least: an arc processing chamber configured to produce and comprise a plasma; a cathode configured to emit electrons to the arc processing chamber; An electrode disposed in the arc processing chamber such that electrons emitted by the cathode are incident thereon; one or more voltage potential sources configured to bias the electrode; and a voltage potential adjuster operable to positively The source of the voltage potential biasing the electrode (as the anode) and the source of the voltage potential negatively biasing the electrode (as the reverse cathode) are switched.

Now, "counter-cathode" does not have a general confirmation. "Anti-cathode" and "reflector" are also the consent words used in the industry. The "reverse cathode" will be used to refer to this electrode below, and the "reverse cathode" used in the patent application should be interpreted in the same way. In fact, the electrode is facing the cathode opposite the arc treatment chamber and is either connected to the cathode potential or electrically isolated so that it floats close to the plasma potential.

In the configuration disclosed herein, an arc is struck between the cathode and the counter cathode (the latter acts as the anode). In addition, the positive bias potential on the reverse cathode attracts the electrons emitted by the cathode to move it to the reverse cathode where it accumulates. Therefore, the electron tends to go back and forth only once to the arc processing chamber (assuming a conventional configuration of the cathode and the counter cathode). The electrons in the arc processing chamber have a shorter average life when compared to conventional configurations with a negative bias cathode and a reverse cathode (in the operation of the reflective mode). In the reflective mode operation, the reverse cathode is maintained at the same potential as the cathode to allow the electrons to be re-reflected. This increases the lifetime of the electrons (emitted by the cathode) in the arc processing chamber to form a more energetic plasma that enhances the ionization and cracking of the source gas molecules. In a novel, non-reflective mode of operation, 7 1336484

The electrons are attracted to the positive and negative cathodes and pooled there. Therefore, life will be reduced in the arc processing room. However, it has been found that reduced electron lifetime leads to molecules such as BF3 as a precursor gas with less B + and production. This means that although the ions generated in the plasma may be less, more fragments are maintained in the BF2+ state. Surprisingly, my reduced cleavage will provide a significant amount of larger ions (eg BF: any loss of overall ion yield. Using B F3 as a precursor can contribute up to 70% of the BF2+ beam current (this It measures the BF2+ ions present in the stage. Therefore, the advantage of this new configuration is that it can be implanted with higher quality molecules such as BF2 + instead of low-quality cracking products. In addition, it can also be selected according to the desired planting. Appropriate operation is based on the implant formula (for example, assisting B + generation or BF2 + production respectively). Alternatively, the ion source may include a vacuum processing chamber piezoelectric position regulator in an atmospheric environment. Switching can be performed without the need to access the voltage potential regulator and the chamber is evacuated to atmospheric pressure. When operating in the non-reflective mode, a negative bias arc is preferred to cause electrons to move to the reverse cathode. The arc processing chamber is biased or electrically isolated to float close to the plasma potential. In the formula, the processing chamber wall is positively biased to provide the anode with the desired electrical output. The ion source may contain an additional voltage potential. The whole device, which can handle the cleavage of the electrons of life. BF + ions, but there will be more people also found that, in order to compensate for the gas mass of the mass of the ion mode, η choose any, and the vacuum between the modes The wall of the processing chamber may also be in the reflection mode ίν. Therefore, the chamber wall is treated with a positive bias of 8 1336484 or a negative bias. Similarly, in order to eliminate the need to evacuate the vacuum processing chamber, the additional voltage The potential adjuster can be located in the atmosphere.

Preferably, for at least the first and second ion generating modes, the ion source is further configurable to operate with the voltage potential adjuster and the additional voltage potential adjuster group to forward bias the reverse cathode respectively The chamber wall is negatively biased and vice versa. This mode corresponds to the non-reflective and reflective modes, respectively. Although selective, the ion source is preferably further configured to switch between the first and second ion generating modes and to recover by operating the voltage potential adjuster and the additional voltage potential adjuster to make the first The switch can typically be biased from negative to positive. This approach ensures that the anode is always available to continue to arc and maintain the plasma in the arc processing chamber. In this manner, the arc processing chamber can be maintained at elevated operating temperatures.

Alternatively, the voltage potential adjuster can be configured to further electrically isolate the reverse cathode, and wherein the ion source can be further configured to interact with the voltage potential adjuster and the additional voltage potential adjuster group for the third ion generation mode An operation is performed to electrically isolate the reverse cathode from positively biasing the arc processing chamber wall. This mode provides a third (floating) mode of operation that allows the potential of the reverse cathode to float to the plasma potential. This approach provides an intermediate level of electronic reflection by the reverse cathode, thus providing intermediate strength cracking. Alternatively, the voltage potential adjuster can be a bidirectional switch configured to switch between a first position (for positive biasing of the reverse cathode) and a second position (for negative biasing of the reverse cathode). Alternatively, the voltage potential adjuster 9 1336484 can be a three-way switch configured to switch to a first position (to positively bias the reverse cathode), a second position (to negatively bias the reverse cathode), and Between the third position (to electrically isolate the reverse cathode). Alternatively, the additional voltage potential adjuster is configured to be switchable between a first position (for positively biasing the arc processing chamber wall) and a second position (for negatively biasing the arc processing chamber wall) Switch. The voltage regulator or switch is selectively configurable such that the arc processing chamber wall and the counter cathode are at the same potential.

Alternatively, the ion source further includes a magnetic component configured to provide a magnetic field in the arc processing chamber to define an electron path for the electrons emitted by the cathode. This mode provides a longer electronic path length for the hot electrons, otherwise the hot electrons are drawn directly into the adjacent arc processing chamber wall while operating at the positive potential of the chamber wall relative to the cathode. The magnetic field forces the electrons to move along the length of the arc processing chamber (e.g., the cathode and the counter cathode are located at opposite ends of the arc processing chamber).

In a second aspect of the invention, it relates to an ion implanter comprising any of the foregoing ion sources. Optionally, the arc processing chamber further includes an outlet and the ion implanter further includes a pumping electrode operable to extract ions from the plasma in the arc processing chamber via the outlet, and the extracted Ions are implanted on the target. Alternatively, the ion implanter may further comprise a mass analysis station configured to pick up ions extracted from the arc processing chamber and operable to set ions of the selected mass and charge state to a specific one. Energy transfer (eg, planting) to the target. In a third aspect of the present invention, there is provided a method of operating an ion source according to the method of 1 10336484, wherein the ion source comprises an arc processing chamber having a cathode and a reverse cathode, the method comprising: a first reflection An operating mode comprising negatively biasing the cathode, positively biasing a chamber wall to plasma between the cathode and the chamber wall, and negatively biasing the counter cathode to repel the electrons; and a second non-reflective operation The mode includes negatively biasing the cathode and positively biasing the reverse cathode to produce a plasma between the cathode and the counter cathode. Preferred features of this method are defined in the scope of the additional patent application.

[Embodiment] FIG. 1 shows an exemplary application of the present invention, and those skilled in the art should understand that this is merely an embodiment of the present invention and is not intended to limit the scope thereof.

1 is a diagram of a conventional ion implanter 10 for implanting ions onto a semiconductor wafer 12, including an ion source 14 in accordance with the present invention. The ions generated by the ion source 14 are drawn and transported through a mass spectrometer 30 in this embodiment. The desired mass of ions is selected through the mass analysis slit 32 and then to the semiconductor wafer 12. The ion implanter 10 includes an ion source 14 for generating an ion beam of a desired species within the vacuum processing chamber 15. The ion source 14 typically includes an arc processing chamber 16 having a cathode 20 at one end. According to conventional techniques, the ion source 14 can be operated to cause the arc treatment chamber 16 wall 18 as an anode. Cathode 20 is then heated sufficiently to form hot electrons. The hot electrons diverging from the cathode 20 are adsorbed to the anode, which in this case is adjacent to the processing chamber wall 18. The hot electrons ionize the gas molecules 11 336 484 as they traverse the arc processing chamber 16 to form a plasma and produce the desired ions. The path followed by the hot electrons is also controlled by conventional techniques to prevent electrons from following only the shortest path to the processing chamber wall 18. The magnetic assembly 46 can provide a magnetic field that extends through the arc processing chamber 16 to cause the hot electrons to follow the spatial path along the length of the arc processing chamber 16 toward the opposite cathode 14 at the opposite end of the arc processing chamber 16.

The gas feed 22 is loaded with an arc treatment chamber 16 with a precursor gas species (e.g., BF3). The arc processing chamber 16 is maintained at a reduced pressure in the vacuum processing chamber 15. The hot electrons moving through the arc treatment chamber 16 ionize the precursor BF3 gas molecules and also cleave the BF3 molecules to form BF2, BF and B molecules and ions. The ions formed in the plasma will also contain traces of contaminant ions (e.g., contaminants formed by the walls of the process chamber).

The ions in the arc processing chamber 16 are taken out of the outlet 28 by the negative biasing of the electrode 26. The power supply 21 applies a voltage difference between the ion source 14 and the subsequent mass analysis stage 30 to accelerate the extracted ions. The ion source 14 and the mass analysis stage 30 are electrically connected to each other by an insulator (not shown). Isolated. The mixture of ions taken will then pass through the mass analysis station 30 to pass the curved path affected by the magnetic field. The radius of curvature of any ion is determined by its mass, charge state, ie energy, and the magnetic field is controlled to have a desired mass to charge ratio at a particular beam energy. The ions and energy can exit along a path that coincides with the mass analysis slit 32. The new ion beam that is derived is then sent to the target, i.e., the substrate wafer 12 to be implanted, or the ion beam file 38 when the target position is free of the wafer 12. In other modes, the ion beam can also be accelerated or decelerated using a lens set (located between the mass analysis station 12 1336484 3 0 and the target position). The semiconductor wafer 12 will be mounted on the wafer support 36, and the wafer 12 will be continuously transferred into and out of the wafer support 36 for continuous implantation. Alternatively, parallel processing can be used to position a plurality of wafers 12 on turntable 36 for rotation to present the wafer to subsequent incident ions. Figures 2 and 3 show two known ion sources 14 in more detail and can be used in the ion implanter 10 of Figure 1. Figure 2 corresponds to a filament configuration and Figure 3 corresponds to an indirectly heated cathode configuration.

Referring first to Fig. 2, a filament 40 as a cathode is placed at one end of the arc processing chamber 16 to be positioned in front of the electron reflector 42. The electronic reflector 42 maintains the same negative potential for the filament 40, negatively biasing both of them and rejecting electrons. There is a small gap between the electronic reflector 42 and the spacer 56, which contains the deepest portion of the arc processing chamber 16. This gap ensures an electronic reflector

4 2 is electrically isolated from the gasket 56 which is usually used as an anode. The tolerance should be minimal to avoid leakage of precursor gases from the arc processing chamber 16. The reverse cathode 44 is located at the extreme end of the arc processing chamber 16 and is also slightly spaced from the spacer 56 to ensure electrical isolation and minimize gas leakage. The magnet assembly 46 (shown only in Figure 1) is operable to provide a magnetic field such that electrons diverging from the filament 40 follow the spatial path 34 in the longitudinal direction of the arc processing chamber 16 toward the counter cathode 44. The arc processing chamber 16 is filled with a precursor gas species by a gas feed 22 or one or more sprayers 23 to heat the solid or liquid. The filament 40 is secured by two clamping portions 48, each of which is coupled to the body 50 of the ion source 14 by an insulating block 52. The insulating block 52 is mounted with a gear 54 to prevent any gas molecules that escape from the arc processing chamber 16 from contacting the 13 1336484 insulating block. It is obvious that the majority of Fig. 3 corresponds to Fig. 2, so the same parts will not be described again. In addition, the same elements will still be denoted by the same reference numerals.

The difference between Figures 2 and 3 is at the top of the arc processing chamber 16, and Figure 3 shows an indirect heated cathode configuration. The cathode is provided on one of the end caps 58 of the tube portion 60 to slightly protrude into the arc treatment chamber 16, and the tube portion 60 contains the heating filament 62. The filament 6 2 and the end cap 58 are heated and maintained at different potentials to ensure that the hot electrons diverging from the filament 62 can be accelerated to the end cap 58, and the gap between the tube portion 60 and the gasket 56 of the arc treatment chamber 16 can be maintained. Electrically isolated. The acceleration of the electron to end cap 58 transfers the energy to the end cap 5 8 to allow it to heat sufficiently to dissipate the hot electrons to the arc processing chamber 16. This configuration is superior to the filament configuration of Figure 3 because the filament 40 wears faster under the influence of reactive ions and ion bombardment of the plasma. To alleviate this problem, the indirectly heated cathode heating filament 62 will be housed within the envelope tube portion 60 so that ions do not contact the heating filament 62. Ion source 14 with a new bias configuration will be described with reference to Figures 4 through 7.

Said. First, see Fig. 4, and the arc processing chamber 16 shown schematically in Fig. 3 is shown next to the power supply 64. The dashed box 66 indicates the boundaries between several components (masked within the vacuum processing chamber 15), and these components are in the atmosphere 7〇. It is obvious that the components in the atmosphere 70 can be adjusted without damaging the vacuum 68. As shown in Figure 4, three consecutive power supplies in atmosphere 70 can supply current to different components of ion source 14 at different potentials. The ion source 1 4 14 1336484 includes an indirectly heated cathode. The filament power supply 72 provides a relatively high current to the filament 62 of the indirectly heated cathode. The bias power supply 74 is used to positively bias the end caps 5 8 relative to the filaments 6 2 to accelerate the thermal electrons radiated by the filaments 6 2 toward the end caps 58. The arc power supply 76 forms an anode by setting a large positive potential with respect to the end cap 58, punching the plasma and then maintaining the plasma. According to conventional techniques, the ion source 14 should operate in a reflective mode with a positive biasing chamber wall 18 as the anode and a negative biasing counter cathode 44 to repel the electrons.

The present invention provides a novel, non-reflective mode of operation in which the reverse cathode 44 is positively biased to act as an anode and the process chamber wall 18 is negatively biased to repel electrons. This potential can be used to direct electrons from the end cap 58 to the counter cathode 44 where the loop is completed. Alternatively, the process chamber wall 18 can be positively biased, or the process chamber wall 18 can be electrically isolated to float to the potential at which the plasma is located.

The ion source of Figure 4 can be operated either in reflection (as shown in Figure 4) or in a non-reflective mode of operation (not shown in Figure 4, but only for switches 6 2 and 8 4 that are relatively switched). Such design flexibility can be achieved by a pair of switches 8 2 and 8 4 such that a positive or negative bias can be applied to the reverse cathode 44 and the process chamber wall 18. The electrical connections extending from the reverse cathode 44 and the process chamber wall 18 provide power connections to the switches 82 and 84, respectively. Switches 82 and 84 can be placed in atmosphere 70 so that the power connection can extend via vacuum feed passage 80 (at vacuum/atmosphere interface 66). By placing switches 82 and 84 in atmosphere 70, it is possible to switch between operating modes without having to pour the vacuum processing chamber 15 into a pouch. It is also possible to use a separate feed channel 80 or a feed channel 80 for a total of 15 1336484. The power connection from the filament power supply 72 and the voltage source supply 74 also passes through the vacuum feed channel 80. The separable feed channel 80, but preferably a single feed channel 80 is used to arrange all power connections. Alternatively, the switches 82, 84 can be disposed within the vacuum processing chamber 15.

Switch 82 is a bidirectional switch that connects reverse cathode 44 to either of a pair of connectors. These connectors are electrically connected to either side of the arc power supply 76 to provide positive and negative bias to the counter electrode 44. A similar configuration can be used for switch 84, i.e., switch 84 can handle chamber wall 18 positively or negatively. Figure 4 shows the ion source 14 operating in a reflective mode. Thus, switch 82 is attached to its negative terminal to bias reverse cathode 44. Switch 84 is then provided to its positive terminal to positively bias process chamber wall 18. For operation in the new non-reflective mode, the positions of switches 8 2 and 8 4 in Figure 4 are only reversed such that reverse cathode 44 is positively biased and process chamber wall 18 is negatively biased. When operating in this mode, it is preferred to turn off the magnet 46 or operate the magnet 46 at a low current.

Operation between the two modes can be switched without the need to extinguish the plasma, as described below. Beginning with the reflective mode of operation illustrated in Figure 4, switch 8 2 will first switch to positively bias the reverse cathode 44 and then switch switch 84 to negatively bias the process chamber wall 18. This method ensures the maintenance of the plasma because there is always a sufficient potential difference between the cathode and the anode. To change from the non-reflective mode of operation to the reflective mode, switch 84 will first switch to positively bias the process chamber wall 18, and then switch switch 82 to negatively bias reverse cathode 44. Again, this approach ensures the maintenance of the plasma. 16 1336484

The fifth drawing generally corresponds to the fourth drawing, so the same components will be described again for the sake of brevity. In addition, the same reference numerals are used to designate the same elements. Fig. 5 shows a configuration similar to that of Fig. 4, but with a lamp instead of an indirectly heated cathode. The fifth source ion source 14 includes a filament disposed in front of the electron reflector 42. Both the filament 40 and the electronic reflector 42 are maintained at the same voltage by a power connection 83 (which can be placed in the vacuum 68). In addition, a separate bias power supply 74 is not required because there is no potential difference between the lamp and the electronic reflector 42. Thus, single arc power source 76 can set the potential of electronic reflectors 42 and 40 relative to wall 18 (or pad 56). Except for this, the embodiment of Fig. 5 corresponds to the embodiment of Fig. 4. The potential of the reverse cathode 44 and the process chamber wall 18 can be switched in two modes of operation. Fig. 6 generally corresponds to Fig. 4, and the same components are not described again, and the same components are denoted by the same reference numerals. The difference between Fig. 6 and Fig. 4 is that the switch 8 2 has been replaced by the three-way switch 8 2 '. Switch 8 2 ' has the same and negative contacts to bias reverse cathode 44 positively and negatively. However, a third joint is also provided which is only used to electrically isolate the reverse cathode 44. This floating mode is only used when the process chamber wall 18 is positive. The ion source 14 can be used in a floating mode of operation. This floating mode of operation provides a moderate sub-life, such that the electrons are no longer strongly reflected by the cathode 44 as the counter-cathode 44 is maintained at a negative bias, but will maintain more electrons at the timing relative to the counter-cathode 44. When the potential of the counter-cathode 44 is maintained at a negative pressure, the arc treatment: will not be 4 Hao 4 0 40, the whole process of the negative-off wire 40 is supplied with the filament I, and the electric opposite is applied before the line. Directional bias t 16 17 1336484

The likelihood of cleavage of the BF3 molecule is increased by the high electron density in the arc processing chamber 16. Therefore, boron ions in the plasma increase with respect to all other ions (e.g., BF and BF2 ions). When the counter-cathode 44 is isolated and floats to the potential set by the plasma, the cracking is reduced to leave more molecular ions (e.g., BF+ and/or BF2+) in the plasma. When the reverse cathode 44 is positively biased, the cracking is even further reduced. As described previously, either the butterfly or BF2 + ions can be preferably used to implant the semiconductor wafer 12. Switching the potential of the reverse cathode 44 maximizes the preferred number of ions incident on the mass analysis station 30 and is therefore forwarded to the semiconductor wafer 12. Thus, the counter cathode 44 can be biased to preferentially form a particular dopant. Figure 7 shows the same three-way switch 8 2 (and the accompanying three modes of operation) applied to the ion source of Figure 5. When switch 8 2 is set to the third joint (as shown), reverse cathode 44 is free to float to the plasma potential within arc processing chamber 16. It will be appreciated by those skilled in the art that the foregoing embodiments may be modified without departing from the spirit of the invention.

It will be appreciated that the aforementioned process chamber wall 18 can also be operated in a positive, negative or electrical isolation manner. Figures 4 through 7 show a bidirectional switch 8 4, 8 4 ' which allows the bias voltage to be converted between positive and negative and restored. When the switches 84, 8 4 ' are replaced by a three-way switch (similar to the switches 8 2 ' of Figures 6 and 7), the three-way switching can be made between positive bias, negative bias and electrical isolation. Although the foregoing embodiment employs switches 8 2 and 8 4 to allow the potential of the reverse cathode 44 and the process chamber wall 18 to be changed by connecting either side of the arc power supply 76, other configurations are possible. For example, the switch 18 1336484 can be used to connect the reverse cathode 44 and/or the process chamber wall 18 to one or more alternative power supplies. The alternative power supply can be any of the types shown in Figures 4 through 7, or it can be an additional power supply. The switch configuration shown above is better because of its simplicity. Other alternatives may be a potential divider, connected to provide a differentiated voltage potential, and a switch operable to connect the reverse cathode 44 to the cathode 20 or one of the differentiated voltage potentials. Further, a variable power supply or a switchable resistor or switchable potentiometer can also be used to provide a selected voltage to the reverse cathode 44 and/or the process chamber wall 18.

Switches 8 2 and 8 4 can be implemented in any standard number of ways. The switches are only examples and there are other possible configurations. It is obvious that the specific configuration of the materials and components used in the structure of the ion source can be selected as desired.

Although the foregoing embodiments of the present invention describe the ion source 14 of the ion implanter, the present invention can also be used in many other applications, such as ion spray systems, in which ions taken from the ion source 14 can be implanted in The target is not required for mass analysis; or any other ion source 14 utilizing a counter-cathode 4 4 wherein selective ionization and/or molecular cleavage can be performed as desired. BRIEF DESCRIPTION OF THE DRAWINGS The method and apparatus examples according to the present invention will be described in detail with reference to the accompanying drawings in which: FIG. 1 is a schematic representation of an ion implanter; FIG. 2 is a side view of a first ion source; Figure 3 is a side view of a second ion source comprising an indirectly heated 19 1336484 cathode configuration; Figure 4 is a schematic representation of an ion source having an indirectly heated cathode configuration illustrating a first embodiment in accordance with the present invention Example of biasing configuration; Figure 5 is a simplified representation of an ion source having a simplified filament configuration, showing a biasing device in accordance with a second embodiment of the present invention. 6 corresponds to FIG. 4, but illustrates a third embodiment of the present invention including a three-way switch for setting a reverse cathode potential; and FIG. 7 corresponds to FIG. 5, but illustrates a fourth embodiment of the present invention. Example contains

A three-way switch for setting the reverse cathode potential. [Main component symbol description] 10 Handler 12 Semiconductor wafer 14 Ion source 15 Vacuum processing chamber 16 Arc processing chamber 18 Processing chamber wall 20 Cathode 2 1 Power supply 22 Gas feeder 23 Sprayer 26 Extraction electrode 28 Opening σ 30 Mass Analysis Table 32 Mass Analysis Narrow 36 Wafer Support 40 Filament 42 Electronic Reflector 44 Reverse Cathode 46 Magnet Assembly 48 Clamping Port 52 Insulation Block 54 Body 56 Pad 58 End Cap 60 Tube 62 Heat Filament 20 1336484 64 Power Supply 66 Dotted Box 68 Vacuum 70 Atmosphere 72 Filament Power Supply 74 Bias Power Supply 76 Arc Power Supply 80 Vacuum Feed Channel 82, ί 2', 84 Switch

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Claims (1)

13.36484 牟月曰Revision and replacement page No.1 Specialization Bamboo Year Revision 10, Patent Application Range: 1. An ion source for an ion implanter, which at least includes an arc processing chamber configured to generate And accommodating a plasma; a cathode configured to diverge electrons into the arc processing chamber; an electrode disposed in the arc processing chamber to direct electrons emitted by the cathode to the portion; one or more a voltage potential source configured to bias the electrode; and a voltage potential adjuster operative to forward the electrode as a two anode step and the voltage potential source to negatively bias the electrode Switching between the steps of a reverse cathode. 2. The ion source of claim 1, further comprising a vacuum processing chamber, and wherein the voltage potential adjuster is located in the atmosphere. 3. The ion source of claim 1, further comprising an additional voltage potential adjuster configured to positively bias an arc processing chamber wall and to negatively bias the arc processing chamber wall Switch between. 4. The ion source of claim 3, further comprising a vacuum processing chamber, and wherein the additional voltage potential adjuster is in the atmosphere. 5. The ion source of claim 3, further configured to utilize at least a first ion generation mode and a second ion generation mode to utilize the electrical 22 1336484 • I qq in 1 4 day correction replacement page piezoelectric position The regulator and the additional set of voltage potential adjusters operate to positively bias the electrode and negatively bias the arc processing chamber wall, and vice versa. 6. The ion source of claim 5, further configured to change between a first ion generation mode and a second ion generation mode, and in turn to operate the voltage potential adjuster and the additional voltage potential The regulator is responsive to return the first switch from a negative bias to a positive bias. 7. The ion source of claim 1, wherein the voltage potential adjuster is configured to further electrically isolate the electrode. 8. The ion source of claim 3, wherein the additional voltage potential adjuster is configured to further electrically isolate the arc processing chamber wall. 9. The ion of claim 5 a source, wherein the voltage potential adjuster is configured to further electrically isolate the electrode, and wherein the ion source is further configured to operate with the voltage potential adjuster and the additional voltage potential adjuster set for a third ion generation mode, The electrodes are electrically isolated and the arc processing chamber walls are positively biased. 10. The ion source of claim 1, wherein the voltage potential 23 1336484 • I 9|October 14th, the Xiong replacement page adjuster is configured to be capable of positively biasing the electrode first A switch that switches between a position and a second position that can negatively bias the electrode. 11. The ion source of claim 7, wherein the voltage potential adjuster is configured to be capable of positively biasing the first position of the electrode once configured, and configured to negatively bias the second electrode of the electrode The position and a switch configured to electrically switch between the third position of the electrode. 12. The ion source of claim 3, wherein the additional voltage potential adjuster is configured to provide a positive potential relative to the cathode to a first position of the arc processing chamber wall and once A switch is provided that provides a switch between a negative potential of the electrode and a second position of the arc processing chamber wall. The ion source of claim 8, wherein the additional voltage potential adjuster is configured to be capable of positively biasing the first position of the arc processing chamber wall, and configured to be negatively biased A second position of the arc processing chamber wall and a switch configured to electrically switch between the third position of the arc processing chamber wall. 14. The ion source of claim 1, wherein the cathode is an end cap of one of the filaments or an indirectly heated cathode type ion source ° 24 1336484 • I ~sorrt- The ion source of claim 14, further comprising an electrode operable as an electron reflector adjacent to the filament of an ion source. 16. The ion source of claim 1, further comprising a magnet assembly configured to provide a magnetic field in the arc processing chamber to define an electronic path of electrons diverging from the cathode. An ion implanter comprising the ion source of any of the preceding claims. 18. The ion implanter of claim 17, wherein the arc processing chamber further comprises an outlet, and the ion implanter further comprises a dip electrode operable to electrically elect the arc via the outlet The plasma contained in the processing chamber extracts ions and transports the extracted ions to be implanted in a target. 19. The ion implanter of claim 18, further comprising a mass analysis station positioned to receive ions extracted from the arc processing chamber and operable to deliver a particular energy transfer Mass and charge ions are implanted into a target. 20. A method of operating an ion source, wherein the ion source comprises an arc processing chamber having a cathode and a reverse cathode, the method comprising the following step 25 1336484 • it* 9W w positive replacement page ___ a first reflective mode of operation comprising: negatively biasing the cathode, positively biasing a chamber wall to strike plasma between the cathode and the chamber wall, and negatively biasing the counter cathode to repel such Electron: and a second non-reflective mode of operation comprising negatively biasing the cathode and positively biasing the reverse cathode to strike plasma between the cathode and the counter cathode. 21. The method of claim 20, further comprising the step of electrically isolating an arc treatment chamber wall in a non-reflective mode of operation. 22. The method of claim 20, further comprising the step of switching from the non-reflective mode to the reflective mode by switching the bias voltage on the wall of the arc processing chamber from a negative bias to a positive The bias is then applied in a manner that the bias on the reverse cathode is biased from positive to negative. 23. The method of claim 22, further comprising the step of separating the reverse cathode to electrically isolate it. 2. The method of claim 20, further comprising switching to a third mode of operation by ensuring that the bias on the wall of the arc processing chamber is positively biased and separating the reverse The cathode is carried out in such a way as to be electrically isolated. 26