TWI592972B - Ion Source With Dual-Hot-Electron Source And Method For Generating Hot Electrons Thereof - Google Patents

Description

Ion source with dual hot electron source and hot electron generating method thereof

The present invention relates to an ion source for an ion implanter, and more particularly to an ion source having a dual thermal electron source.

The ion implanter is used in the semiconductor process to ion implant the region to be doped in the semiconductor wafer, and the ion source in the ion implanter is used to generate an ion beam for ion implantation, and currently There are two types of ion sources according to different thermoelectric generation methods: one Berna Ion Source and the other Indirectly-Heated-Cathode Ion Source (IHC Ion Source).

Referring to FIG. 6A, the thermoelectron source of the Berner-type ion source directly adopts a filament 62 which penetrates from the side of the outer casing 61 of the arc chamber 60 and is fixed to the inner plate 611 of the side. . When a filament power supply unit 70 supplies current to the filament 62, the temperature of the filament 62 rises, and electrons are generated when the temperature of the filament 62 rises to a certain high temperature (e.g., the temperature is greater than 1000 degrees Celsius). At this time, the positive and negative electrodes of an arc power supply unit 72 are respectively coupled to the inner plate 611 of the arc chamber 60 of the ion source and the filament 62, and an electron accelerating electric field is formed in the arc chamber 60 to attract the The electrons of the filament 62 are in the arc chamber 60, and the dopant source gas in the arc chamber 60 is ionized to generate different kinds of ions. Since the voltage supplied from the arc power supply unit 72 to the inner plate 611 of the arc chamber 60 falls within a voltage range of 60V to 150V, the energy of the electrons passing through the acceleration electric field is greatly increased to become high energy. The hot electrons and high-energy hot electrons can strike the doping source gas multiple times to produce positively or negatively charged ions of different valence; wherein the positively charged ions are also attracted by the accelerating electric field, and the outward emission is improved. energy. The high energy ions will sputter the filament 62 multiple times, causing the filament 62 to be damaged and requiring replacement.

In order to increase the service life of the filament 62, the arc chamber 60' of the cathode ion source is indirectly heated as shown in FIG. 6B, wherein the source of the hot electrons further comprises a metal mask covering the filament 62, and the arc power supply is supplied The negative electrode of unit 72 is coupled to be used as cathode 621 (hereinafter collectively referred to as cathode). After the filament 62 is heated to emit electrons, since the cathode 621 is connected to the positive electrode of a bias current power supply unit 71 to have a positive potential, and the electrons emitted from the filament 62 are accelerated, the electrons whose energy is increased will continuously hit the cathode 621. On the outside, the temperature of the cathode 621 is increased; similarly, when the cathode 621 is heated to a certain temperature, electrons are emitted, and the electrons are attracted by the accelerating electric field formed by the voltage supplied from the arc power supply unit 72, thereby becoming a high-energy heat. Electrons are emitted to the arc chamber 60'. Since the high-energy hot electrons also ionize the dopant source gas in the arc chamber 60' to generate positive and negative ions, the positively charged ions are also subjected to an acceleration electric field and reverse acceleration toward the cathode 621, thereby sputtering the cathode. The inner side of the 621 can prevent the filament 62 from being directly splashed by ions, but after a period of time, the cathode 621 is also broken down and needs to be replaced; therefore, the arc chamber of the single set of thermoelectric source structures of FIGS. 6A and 6B 60, 60', the ion concentration of the discharge space will be concentrated on the side where the hot electron source is disposed, and the closer the ion concentration is to the hot electron source, the higher the concentration of ions will present a single high concentration ion splash effect.

Regardless of the structure of the hot electron source of FIG. 6A or FIG. 6B, it is a consumable material for the ion source, and therefore many manufacturers have invested in the development of a technology for prolonging the service life of the hot electron source, and the Taiwan Indirect Heating Electrode No. I450303 The cathode of the ion implanter is known from the invention patent (as shown in Fig. 7), and a cathode 80 is thickened by the intermediate front end 801 of the Repeller 81 on the other side of the arc chamber. Extend the time of erosion by ion squirting and extend the service life. Another example is the utility model patent “Ion Source and Ion Implanter” (shown in Figure 8) of CN203631482, which also increases the diameter and thickness of the front end 801' of the cathode 80' to increase the service life of the cathode. Taiwan Announcement Inventive patent No. I493590, "A device and method for extending the service life of an ion source", as shown in Fig. 9, is to set two or more sets of hot electron sources 80a, 80b in the arc chamber, but only one group is used at a time. The hot electron source 80a, until the set of the hot electron source 80a fails, switches to use the second set of the hot electron source 80b, but needs to replace the relative position of the repellent pole 81 with a rotating structure 811 to continue the ionization; therefore, The invention patent No. I493590 actually extends the time for replacement of the hot electron sources 80a, 80b by switching between different sets of thermoelectron sources 80a, 80b, for which the service life of a single set of thermoelectron sources is not extended.

It can be seen from the above description that the current technology for actually extending the service life of the hot electron source is still mainly based on structural improvement, but it is necessary to produce cathodes of different sizes and specifications, and the actual life extension time is limited. The technique proposed in the invention patent No. I493590 can extend the time for replacing the hot electron source in the ion source, but it is necessary to monitor whether the hot electron source in use has failed, so as to immediately switch to another standby hot electron source; Further increase in the arc chamber to increase the rotating structure to match different hot electron source locations to maintain normal use. Therefore, how to extend the service life of the hot electron source without changing the design of the arc chamber structure is a technical problem that is highly sought after in the art.

In view of the above-mentioned technology for prolonging the service life of the hot electron source of the ion source, it is necessary to change the structure of the arc chamber; therefore, the main purpose of the present invention is to provide a double extension of the service life of the hot electron source without changing the structure of the arc chamber. An ion source of a hot electron source and a method of generating the same.

The main technical means for achieving the above purpose is that the ion source having the dual hot electron source comprises: an arc chamber comprising: a body having a discharge space; a first source of thermal electrons penetrating from a first side of the body and electrically insulated from the first side for exposure to a discharge space of the body; and a second source of thermal electrons from the body a second side is penetrated and electrically insulated from the second side to be exposed in the discharge space of the body; and a power supply device includes: a heating power supply unit coupled to the first And a second source of thermal electrons, forming a current loop; and an arc power supply unit coupled to the body of the arc chamber and the first and second sources of thermal electrons; wherein the arc power supply unit is simultaneously provided to fall at 20V An output voltage between the voltage ranges up to 45V is applied to the first and second sources of thermionics.

The above-mentioned invention mainly reduces the voltage of the arc power supply unit of the ion source to fall between the voltage range of 20V to 45V, and provides the acceleration electric field between the body of the arc chamber and the first and second heat electron sources respectively. The energy of electrons and ions is weakened. Since the energy generated by the ions generated in the body of the arc chamber is weakened toward the first and second hot electron sources, the splashing of the first and second hot electron sources is reduced to relatively extend the first and second The lifetime of the hot electron source. Furthermore, since the electrons generated by the first and second hot electron sources are weaker in energy by accelerating the electric field, low-energy hot electrons can be prevented from repeatedly striking the ionized ions, thereby effectively reducing unnecessary divalent or trivalent Positively charged ions increase the proportion of useful ions in the ion beam (extraction current).

The main technical means for the purpose of the present invention is that the ion source comprises an arc chamber, the body of the arc chamber has a discharge space, wherein the two sides of the body are electrically insulated with two sources of thermal electrons; The method for generating a hot electron includes: providing a heating power source to the two sources of hot electrons, and heating the source of the hot electrons to a first predetermined temperature to emit the hot electrons; Providing an arc power to the body and each of the hot electron sources to accelerate the attraction of the hot electrons emitted by the two hot electron sources to the discharge space of the arc chamber; wherein the arc power supply is provided in a voltage range of 20V to 45V The voltage between them.

The above-mentioned invention mainly reduces the voltage of the arc power source so as to fall between the voltage ranges of 20V to 45V, so that the body of the arc chamber is respectively supplied to the accelerating electric field between the first and second thermoelectron sources and The energy of the ions is weakened, and the splashing effect of the low-energy ions on the first and second hot electron sources is moderated to extend the service life of each of the first and second hot electron sources, and the low-energy hot electrons It can avoid the hot electrons from hitting the ionized ions multiple times, effectively reducing the unnecessary divalent or trivalent positively charged ions, and relatively increasing the proportion of ions required in the ion beam (extraction current).

1‧‧‧Ion source

10, 10' ‧ ‧ arc chamber

100‧‧‧discharge space

100a‧‧‧Ion Beam

11‧‧‧Shell

111‧‧‧ bottom air intake

12, 12a, 12b‧‧‧ inner board

14, 14'‧‧‧Hot electron generating components

141‧‧‧filament

142‧‧‧ cathode

20, 20'‧‧‧ Heat sink

21‧‧‧Solution body

211‧‧‧ top surface

212‧‧‧ bottom

213‧‧‧ side

214‧‧‧ Short side

215‧‧‧ Groove

216‧‧‧ space

22‧‧‧Cooling medium tube

221, 222‧‧‧ branch

30‧‧‧Base

301‧‧‧ top surface

31‧‧‧Lower base

40‧‧‧Intake pipe

50, 50'‧‧‧Power supply unit

51‧‧‧ filament power supply unit

52‧‧‧Non-current power supply unit

53‧‧‧Arc Power Supply Unit

60, 60' ‧ ‧ arc chamber

61‧‧‧Shell

611‧‧‧ inner board

62‧‧‧filament

621‧‧‧ cathode

63‧‧‧ Rejection

70‧‧‧ filament power supply unit

71‧‧‧Non-current power supply unit

72‧‧‧Arc Power Supply Unit

80, 80'‧‧‧ cathode

80a, 80b‧‧‧thermal electron source

801, 801’‧‧‧ front end

81‧‧‧ Rejection

811‧‧‧Rotating structure

Figure 1 is a perspective view of an ion source of the present invention.

2A is a schematic view showing the electrical connection between an arc chamber and a power supply device of a Berner-type ion source according to the present invention.

2B is a schematic view showing the electrical connection of an arc chamber and a power supply device for indirectly heating a cathode ion source.

Figure 3: A partial cross-sectional view of Figure 1.

Figure 4 is a perspective view of a first preferred embodiment of the heat sink of the present invention.

Figure 5 is a perspective view of a second preferred embodiment of the heat sink of the present invention.

Figure 6A: A perspective view of an indirect heated cathode ion source.

Figure 6B is a schematic view showing the electrical connection between the arc chamber and the power supply device of the indirectly heated cathode ion source

Figure 7: Second diagram of the invention patent of Taiwan Announcement No. I450303.

Figure 8: Figure 3 of the utility model patent No. CN203631482 in mainland China.

Figure 9: Figure 1A of the Taiwan Patent Publication No. I493590.

The invention is based on a structure which does not change the source of the hot electrons in the ion source of the ion implanter, and proposes an ion source with a dual hot electron source and a method for generating the same, which prolong the service life of the hot electron source.

1 is a perspective view of an ion source 1 of the present invention, which is mainly provided with a heat dissipating device 20 and an arc chamber 10 on a top surface 301 of a pedestal 30; As shown in FIG. 2A, the first preferred embodiment of the arc chamber 10 of the present invention is further electrically connected to an external power supply unit 50. The arc chamber 10 includes a body, a first source of thermal electrons 14a and a second heat. The electronic power source 14b; the power supply device 50 used in conjunction with the embodiment includes a filament power supply unit 51 and an arc power supply unit 53.

Referring to FIG. 2A and FIG. 3 together, in the embodiment, the system includes a casing 11 and a plurality of inner plates 12, 12a, 12b. The first thermoelectron source 14a is worn from a first side of the body. The second heat electron source 14b penetrates into the outer casing 11 and the corresponding inner plate 12b from a second side of the body, and is electrically insulated and fixed to the first side of the body. Electrical insulation is secured to the second side of the body. In the present embodiment, each of the first and second thermoelectron sources 14a, 14b includes a filament 141 that is directly exposed to the discharge space 100 of the arc chamber 10.

The filament power supply unit 51 is coupled to the filaments 141 of the first and second thermoelectron sources 14a, 14b to form a current loop. The arc power supply unit 53 is coupled to the inner panel 12 of the body and the first and second thermoelectron sources 14a, 14b; wherein the arc power supply unit 53 provides an output voltage falling between 20V and 45V . In this embodiment, the filaments 141 of the first and second hot electron sources 14a, 14b are connected to one another at one end, and the other end is respectively supplied with the filament power supply. The positive electrode (+) and the negative electrode (-) of the unit 50 are connected to form the current loop, and the negative electrode (-) of the arc power supply unit 53 is connected to the current loop to be coupled to the first and the The two hot electron sources 14a, 14b, and their positive electrodes (+) are coupled to the inner panel 12 of the body.

In the present embodiment, although the arc chamber 10 includes first and second sources of thermal electrons 14a, 14b, one of the sources of thermal electrons 14b is disposed at a repulsive pole position of the existing arc chamber; The body structure of the arc chamber 10 has not been altered. When the filament power supply unit 51 supplies current to the current loop, the filaments 141 of the first and second thermoelectron sources 14a, 14b are heated to a certain temperature and then radiate hot electrons into the discharge space 100 of the arc chamber 10. Then, when the arc power supply unit 53 provides an output voltage between the voltage ranges of 20V to 45V, an accelerating electric field can be established between each of the filaments 141 and the inner plates 12, 12a, 12b, so that the filaments on both sides of the body The electrons generated by 141 are acceleratedly emitted into the discharge space 100 of the arc chamber 100, and ionization of the doped source gas generates several ions.

Since the present invention reduces the voltage supplied to the arc power source of the arc chambers 12, 12a, 12b, the body of the arc chamber 10 and the accelerating electric field between the first and second thermoelectron sources 14a, 14b, respectively. The energy provided to the electrons and ions is attenuated; wherein the low energy ions can reduce the sputtering of the filaments 141 of each of the first and second hot electron sources 14a, 14b to extend the life of the filament 141. Similarly, since the energy of the hot electrons decays after the impact, for low-energy hot electrons, the energy is reduced after one impact, thereby reducing the chance of the monovalent ions colliding with the divalent or trivalent ions. Effectively reduce unnecessary divalent or trivalent positively charged ions, and relatively increase the proportion of ions required in the ion beam (extraction current). According to the present invention, the first and second thermoelectron sources 14a, 14b are respectively disposed on the first side and the second side of the body of the arc chamber 10, so that the electrons can be simultaneously emitted to the discharge space 100, and the discharge space 100 is more uniformly ionized. Doped source gas.

In summary, the method for generating an ion source hot electron according to the first embodiment of the present invention includes: providing a heating power source to the two filaments 141, and heating each of the filaments 141 to a certain temperature to generate electrons, and from the body Transmitting the hot electrons laterally to the discharge space 100; and providing an arc power source The body and each of the filaments 141, wherein the body is coupled to a positive electrode of the arc power source to accelerate the attraction of electrons generated by the two side filaments 141; wherein the arc power source provides a voltage that falls between a voltage range of 20V to 45V.

Referring to FIG. 2B, it is a second preferred embodiment of the arc chamber 10' of the present invention. The structure of the arc chamber 10 is substantially the same as that of the first preferred embodiment shown in FIG. 2A. The second hot electron source 14a', 14b' further includes a cathode 142 to cover its corresponding filament 141 to prevent the filament 141 from being directly exposed to the discharge space 100; in addition, the power source used in the arc chamber 10' of the present embodiment is used. The supply device 50' further includes a bias current power supply unit 52. One ends of the cathodes 142 of the first and second hot electron sources 14a', 14b' are connected to each other, and the other end of the cathode 142 is coupled to the positive electrode (+) of the bias power supply unit 52 and the The negative electrode (-) of the arc power supply unit 53. The negative electrode (-) of the bias current supply unit 52 is coupled to the current loop, i.e., the filament 141 coupled to the first and second sources of thermal electrons 14a', 14b'.

When the filament power supply unit 51 outputs a current to the current loop, heating the filaments 141 of the first and second thermoelectron sources to a first predetermined temperature, and emitting electrons to the discharge space; at this time, the bias current power supply unit The positive and negative electrodes (52) of (52) are coupled to the cathode 142 and the filament 141, respectively, to establish an accelerating electric field between each of the cathodes 142 and the corresponding filaments 141 to attract the filaments 141. The radiant heat electrons strike the corresponding cathode 142 to heat the cathode 142; after the cathode 142 is heated to a second predetermined temperature, hot electrons are emitted into the arc chamber 100. The positive and negative electrodes (+) and (-) of the arc power supply unit 53 are respectively coupled to the plurality of inner plates 12, 12a, 12b and the cathode 142; wherein the arc power supply unit 53 is provided to fall between 20V and 45V. An output voltage between the voltage ranges establishes an accelerating electric field between each of the cathodes 142 and the inner plates 12, 12a, 12b, so that the hot electrons of the cathode 142 are acceleratedly emitted into the discharge space 100, and the access is The dopant source gas is ionized uniformly to produce several ions.

In summary, the ion source hot electron generating method of the second embodiment of the present invention includes: providing a heating power source to the two filaments 141 to heat each of the filaments 141 to a first predetermined temperature to emit electrons; and providing a bias current Each of the cathodes 142 and the corresponding filaments 141 are coupled to the positive electrode of the bias current source to attract electrons emitted by the filament 141 to increase the temperature of the cathode 142 to reach a second predetermined temperature. That is, emitting hot electrons to the two sides of the arc chamber 10'; and providing an arc power source to the plurality of inner plates 12, 12b, 12b and each of the cathodes 142, wherein the plurality of inner plates 12, 12b, 12b are coupled to the The positive electrode of the bias current source is configured to accelerate the attraction of the hot electrons on both sides; wherein the arc power source provides a voltage that falls between the voltage range of 20V to 45V.

The dopant source gas suitable for use in the present invention may be one of ruthenium tetrafluoride, decane, boron trifluoride, diborane, ruthenium tetrafluoride, decane, arsine or phosphine. In addition, the doping source gas suitable for the present invention may also be a doping constituent gas synthesized by a doping gas and a supplementary gas, and the doping gas is barium tetrafluoride, germanium, boron trifluoride, and two. Borane, ruthenium tetrafluoride, decane, arsine or phosphine, the make-up gas is argon, hydrogen, nitrogen, helium, ammonia, fluorine or helium; that is, each of the dopant gases can be combined with the One of the supplemental gases is co-mixed into the doping constituent gas for use as the doping source gas of the present invention; or, each of the doping gas and one of the supplementary gases may be separately used to flow into the arc together The chamber is configured to constitute a co-flow gas and can also be used as the dopant source gas of the present invention.

The following further demonstrates that after performing experimental measurements on several different dopant source gases, the preferred arc power supply voltage is:

When the doping source gas introduced from the arc chamber contains boron trifluoride (BF3) or the doping source gas is boron trifluoride (BF3), the voltage of the arc power source is 30V to 45V.

When the doping source gas introduced from the arc chamber contains arsine (AsH3) or phosphine (PH3), the voltage of the arc power source is 25V to 40V.

When the doping source gas introduced from the arc chamber contains germanium tetrafluoride (SiF4), the voltage of the arc power source is 25V to 40V.

It can be seen from the above that the accelerated electric field established by the lower arc power supply voltage of the present invention causes the thermal electron energy generated by the hot electron generating element to be relatively weakened. Theoretically, the energy required to strike the first valence electron at the outermost periphery of the doping source gas from the front side of the hot electron is not high, and it is only necessary to supply the energy of the hot electron from an accelerated electric field of 8V to 15V, but if Further knocking away from the second valence electron of the doped source gas, the hot electron requires an acceleration electric field of 22V or more to provide more energy to achieve. However, the direction of impact of the hot electrons cannot be controlled. Therefore, based on the impact force of the hot electrons and the extraction current (ion beam) of a certain size, the voltage of the adjusting arc power supply of the present invention falls between the voltage ranges of 20V to 45V, which is equivalent. A large opportunity to at least strike the first valence electron at the outermost periphery of the dopant source gas; therefore, although the present invention reduces the voltage of the arc power source compared to the existing ion source, the energy for producing the hot electron is relatively low, but Because the lower energy hot electrons decay after the impact, the chance of hitting the divalent or trivalent ions can be reduced.

Boron trifluoride is used as an arc chamber (a single set of thermoelectron sources) and a plasma chamber (a single set of thermoelectron sources) that pass through the second embodiment of the present invention; wherein the arc power supply of the present invention is set The voltage is 40V, and the arc power supply voltage of the arc chamber is 85V. Then, six sets of small to large arc power supply currents (in order to increase the power) are adjusted, and the extraction current (ion beam) of the arc chamber is performed. The measurement of the ROI current of the monovalent boron ion (B ⁺ ); wherein the ROI current refers to the terminal current available for implantation on the surface of the wafer is called the ROI current (ROI), the actual measurement result As shown in Table 1 below.

As can be seen from the above Table 1, when the voltage of the arc power supply is set to 40V, and the voltage of the existing arc power source is set to 85V, the extraction current measured by using boron trifluoride as the arc chamber is also useful. The ROI current value of the monovalent boron ion is obviously comparable to the same extraction current (20 mA, 25 mA, 30 mA, 35 mA, 40 mA, 45 mA) in each group, and the ROI current value of the monovalent boron ion of the present invention is indeed Higher than existing ion sources.

As for the service life of the hot electron source, the same extraction condition produces a 35 mA extraction current and is tested using a cathode having a thickness of 0.3 inch. If the cathode of the present invention is shown in Table 2 below, the thickness of the cathode is from 0.3 inches to 45. The day will be reduced to 0.28 inches, while the existing arc chamber will start from the 0.3 inch cathode to the cathode 0.0 inch (breakdown) for only 29 days; therefore, the present invention can effectively extend the life of the cathode.

The pre-measurement data is obtained by measuring a single set of thermoelectron sources in the arc chamber of the second preferred embodiment of the present invention, and the arcs of the two sets of thermoelectron sources 14a', 14b' are installed as shown in FIG. 2B. In chamber 10', due to the increase in the total amount of hot electrons generated, the ROI current value of the higher monovalent boron ion can be measured compared with the above table 1; in addition, the ion concentration is concentrated on the side of the single group of the hot electron source. The arc chamber, the two sets of thermoelectron sources 14a', 14b' of FIG. 2B of the present invention can uniformly distribute the generally generated ions on both sides of the discharge space 100, and is higher than the single arc chamber in which a single set of thermoelectron sources are disposed. The concentration ion splash effect, the arc chamber 10' shown in FIG. 2B of the present invention can effectively disperse the high concentration ion sputtering effect on the two sets of the hot electron sources 14a', 14b', so that the splash effect is halved. In order to greatly extend the number of days of use of the cathode 142 shown in Table 2, the life of the arc chamber 10' can also be increased.

Referring to FIG. 1 and FIG. 3 again, the ion source 1 of the present invention is fastened to the base 30 by the plurality of elastic hook assemblies, that is, the lower substrate 31 of the base 30. The screw is provided with four equidistant L-shaped fixing members 32, one end of a spring 33 is hooked on each of the fixing members 32, and the other end of the spring 33 is hooked to one end of a hook strip 34, and the other end of the strip 34 is formed. There is a hook portion 341 for hooking the two opposite long sides of the extraction electrode plate 13 of the arc chamber 10, and receiving a restoring force of the spring 33 after the fastening, the arc chamber 10 and the heat sink 20 therebelow It can be fastened to the top surface 301 of the base 30.

When the power of the arc power source is increased, the temperature of the arc chamber is increased. Therefore, the present invention uses a heat dissipating device 20 having a high heat dissipation, and the heat dissipating device 20 includes a heat dissipating body 21 and at least one cooling medium tube 22. The bottom surface 212 of the heat dissipation body 21 is disposed on the top surface 301 of the base 30, and the top surface 211 is flush with the bottom surface of the arc chamber housing 11 in a full plane, as shown in FIG. 4, the embodiment of the present embodiment The two opposite short sides 214 of the heat dissipating body 21 are respectively tapered downwardly and inwardly from the top surface 211, and the bottom surface 212 of the heat dissipating body 21 is smaller than the top surface 211; and as shown in FIG. 5, it is another heat dissipating device 20'. In an embodiment, the lower portion of the two opposite short sides 214 of the heat dissipation body 21 is recessed downwardly into a space 216, and the bottom surface 212 of the heat dissipation body 21 is smaller than the top surface 211; compared to the implementation of the heat sink 30 shown in FIG. For example, it can be fast The heat that conducts the arc chamber 10 to the top surface 211 of the heat dissipation body 21 is concentrated more quickly to the middle of the heat dissipation body 21. In addition, in order not to interfere with the air intake pipe 40, as shown in FIG. 3, the heat dissipating body 21 is concavely disposed with a recess 215 corresponding to a side surface 213 of the intake pipe 40, and the recess 215 is penetrated. The top surface 211 and the bottom surface 212 of the heat dissipation body 21 have a distance between the outer tube wall of the air inlet tube 40 and the inner wall surface of the recess 215, so that the air inlet tube 40 does not contact the heat dissipation body 21. Each of the cooling medium tubes 22 passes through the heat dissipation body 21, and passes through the two tubes 221 and 222 from the bottom surface of the heat dissipation body 21, and is inserted into the base 30 from the top surface 301 of the base 30, and is externally connected. A cooling medium (not shown). Furthermore, one of the tubes 221 serves as a cooling medium inlet tube; the other tube 222 serves as a discharge tube for the cooling medium, so that the cooling medium can flow in the cooling medium tube 22. Preferably, the cooling medium can be a cooling gas or a cooling liquid.

In summary, the heat dissipating device 20, 20' of the present invention is mainly flattened on the bottom surface of the arc chamber 10, and in addition to providing a more stable support, the arc chamber is provided with a high thermal conduction efficiency by a larger contact area, and then cooperates. The cooling medium in the cooling medium tube 22 quickly displaces the tropical heat dissipating body 21 to make the overall heat dissipation efficiency better. Moreover, since the heat dissipating device 20, 20' is mainly flattened to the bottom surface of the arc chamber 10 Even if the outer casing is not easily deformed by heat under high temperature operation, the bottom air inlet hole of the arc chamber can be further prevented from being blocked by using some heat cracking doping gas.

The above is only the embodiment of the present invention, and is not intended to limit the scope of the present invention. The present invention has been disclosed by the embodiments, but is not intended to limit the invention, and any one of ordinary skill in the art, In the scope of the technical solutions of the present invention, equivalent modifications may be made to the equivalents of the embodiments of the present invention without departing from the technical scope of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments are still within the scope of the technical solutions of the present invention.

10‧‧‧Arc chamber

100‧‧‧discharge space

11‧‧‧Shell

12, 12a, 12b‧‧‧ inner board

14a‧‧‧First hot electron source

14b‧‧‧Second hot electron source

141‧‧‧filament

50‧‧‧Power supply unit

51‧‧‧ filament power supply unit

53‧‧‧Arc Power Supply Unit

Claims (12)

An ion source having a dual thermal electron source, comprising: an arc chamber comprising: a body having a discharge space; a first source of thermal electrons penetrating and electrically insulating from a first side of the body Fixed to the first side for exposure to the discharge space of the body; and a second source of thermal electrons penetrating from a second side of the body and electrically insulated from the second side for exposure to the second side a power supply device includes: a heating power supply unit coupled to the first and second hot electron sources to form a current loop; and an arc power supply unit coupled Connecting to the body of the arc chamber and the first and second sources of thermal electrons; wherein the arc power supply unit simultaneously supplies an output voltage falling between a voltage range of 20V to 45V to the first and second sources of thermal electrons. The ion source of claim 1, wherein: the first thermoelectron source comprises a filament; the second thermoelectron source comprises a filament, one end of which is connected to one end of the first thermoelectron filament; the heating The power supply unit comprises a filament power supply unit, wherein the positive and negative electrodes are respectively connected to the other ends of the filaments of the first and second thermoelectron sources to constitute the current loop; and the negative electrode system of the arc power supply unit Connected to the current loop to couple with the filaments of the first and second thermoelectronic sources, and the positive electrode is coupled to the body. The ion source of claim 1, wherein: the first thermoelectron source comprises a filament and a cathode covering the filament of the first thermoelectron source; The second source of thermal electrons includes a filament and a cathode covering the filament of the second source of thermal electrons; wherein one end of the filament of the second source of thermal electrons is coupled to one end of the filament of the first thermoelectron, and The cathode of the second thermoelectron source is connected to the cathode of the first two-electron electron source; the heating power supply unit comprises: a filament power supply unit, wherein the positive and negative electrodes are respectively connected to the first and second heats The other end of the filament of the electron source to constitute the current loop; and a bias current power supply unit having a positive electrode connected to one of the cathodes and a negative electrode connected to the current loop for the first and second hot electrons a filament of the source is coupled; and a negative electrode of the arc power supply unit is coupled to the positive electrode of the bias current power supply unit to be coupled to the cathodes of the first and second sources of thermal electrons, and the positive electrode is coupled to the cathode Ontology. The ion source according to any one of claims 1 to 3, wherein: when the doping source gas introduced from the arc chamber contains boron trifluoride (BF3), the output voltage of the arc power supply unit is 30V to 45V; when the doping source gas introduced from the arc chamber contains arsine (AsH3) or phosphine (PH3), the output voltage of the arc power supply unit is 25V to 40V; and when passing from the arc chamber The doped source gas contains antimony tetrafluoride (SiF4), and the output voltage of the arc power supply unit is 25V to 40V. The ion source according to any one of claims 1 to 3, wherein: a doping source gas which is mixed with boron trifluoride (BF3) and a supplemental gas, which is supplied from the arc chamber, the arc power source The output voltage of the supply unit is 30V to 45V; when a doping source gas which is mixed with a hydrogen arsenide (AsH3) or phosphine (PH3) and a supplemental gas, which is supplied from the arc chamber, the arc power supply The output voltage of the unit is 25V to 40V; and a doping source gas which is mixed with silicon tetrafluoride (SiF4) and supplemental gas introduced from the arc chamber, the output voltage of the arc power supply unit is 25V To 40V. The ion source according to any one of claims 1 to 3, further comprising: a base having an intake pipe protruding from a top surface thereof; and a heat dissipating device disposed on a top surface of the base and the arc chamber Between the bottom surfaces of the body. The heat sink according to claim 6, wherein the heat dissipating device comprises: a heat dissipating body, wherein a bottom surface thereof is disposed on a top surface of the base, and a top surface thereof is flatly flushed on a bottom surface of the arc chamber body, the heat dissipating body a recess penetrating the top surface of the intake pipe and the bottom surface thereof is disposed inwardly, and the outer pipe wall of the air inlet pipe has a distance from the inner wall surface of the groove; and at least one cooling medium pipe is The heat dissipation body passes through the two tubes from the bottom surface of the heat dissipation body, and each of the cooling medium tubes is filled with a flowing cooling medium through the two tubes. A method for producing a hot electron with an ion source of a dual thermal electron source, the ion source comprising an arc chamber having a discharge space, wherein the two sides of the body are electrically insulated with two sources of thermal electrons The hot electron generating method includes: providing a heating power source to the two hot electron sources, heating each of the hot electron sources to a first predetermined temperature to emit hot electrons; and providing an arc power source to the body and each of the a source of hot electrons to accelerate the attraction of the hot electrons emitted by the two sources of thermal electrons to a discharge space of the arc chamber; wherein the arc source provides a voltage that falls between the voltage range of 20V to 45V. The method of claim 2, wherein each of the thermoelectron sources comprises a filament exposed to an inner space of the body; wherein: in the step of providing a heating power source to the two thermoelectronic elements, a heating power source is provided to each of the filaments to emit hot electrons from the two sides of the body to the discharge space; and in the step of providing arc power to the body and each of the hot electron sources, the arc power source is supplied to the body And each of the filaments. The method of claim 3, wherein each of the hot electron sources comprises a filament exposed to an inner space of the body and a cathode covering the corresponding filament; wherein: providing the heating power to the two In the step of the hot electronic component, the heating power source is supplied to each of the filaments; and the hot electron generating method further comprises: providing a bias current power to each of the cathodes and the filaments, wherein each of the cathodes is coupled to the bias current a positive electrode of the power source for attracting hot electrons emitted by the corresponding filament to increase the temperature of the cathode to reach a second predetermined temperature, that is, to emit hot electrons to the discharge space; and providing arc power to the body and each of the above In the step of the hot electron source, the arc power source is supplied to the body and each of the cathodes. The method of producing a hot electron according to any one of claims 8 to 10, wherein when the doping source gas introduced from the arc chamber contains boron trifluoride (BF3), the voltage of the arc power source is 30V to 45V. When the doping source gas introduced from the arc chamber contains arsine (AsH3) or phosphine (PH3), the voltage of the arc power source is 25V to 40V; and when doping from the arc chamber The source gas contains germanium tetrafluoride (SiF4), which has a voltage of 25V to 40V. The method of producing a hot electron according to any one of claims 8 to 10, wherein: a doping source gas which is mixed with boron trifluoride (BF3) and a supplemental gas, which is introduced from the arc chamber, The voltage of the arc power source is 30V to 45V; when a doping source gas is formed by mixing arsine (AsH3) or phosphine (PH3) and a supplemental gas from the arc chamber, the voltage of the arc power source It is 25V to 40V; and a doping source gas which is mixed with silicon tetrafluoride (SiF4) and a supplemental gas which is supplied from the arc chamber, and the voltage of the arc power source is 25V to 40V.