Electric arc chamber power supply control system of ion source of ion implanter

Abstract

The utility model discloses an arc chamber power supply control system of an ion source of an ion implanter, which comprises an arc chamber, a power supply device, a filament and a cathode, the filament and the cathode are arranged at one end of the arc chamber, source magnetic devices are further arranged on the outer sides of the two ends of the arc chamber, and the power supply device comprises a filament power supply, a resistor R1 is connected in parallel between the current monitoring port of the filament power supply output end and the common end; the anode and the cathode of the cathode power supply are respectively coupled with the cathode and one end of the filament, and a resistor R2 is connected in parallel between the current monitoring port of the output end of the cathode power supply and the common end; the positive and negative electrodes of the arc power supply are respectively coupled with the arc chamber wall and the cathode, and a resistor R3 is connected in parallel between the voltage output positive electrode and the voltage output negative electrode of the output end of the arc power supply; the advancing path of electrons is changed through the source magnetic device, so that the electrons advance in the arc chamber in a spiral mode, the probability that the electrons collide with doped gas molecules is increased, and meanwhile, the stability of output voltage and current of each direct-current power supply can be effectively improved through the three resistors R1, R2 and R3.

Description

Technical Field

[0001] The utility model relates to the technical field of ion implantation for chip manufacturing, in particular to an arc chamber power supply control system of an ion source of an ion implantation machine. Background Art

[0002] Ion implanters for chip manufacturing use ion implantation to achieve the key process of chip manufacturing, namely doping. Doping ions are generated by the ion source device of the ion implanter through an ionization process, and the required doping ions are selected by a magnetic deflection device. After focusing and accelerating devices, an ion beam with the required energy and density is obtained to implant doping into the silicon wafer.

[0003] The process of generating doped ions is the ionization process, and ionization occurs in the arc chamber of the ion source device. The filament power supply provides sufficient current to heat the filament, and the electrons emitted by the filament heat the cathode until the cathode emits electrons. At the same time, the arc power supply provides a forward bias DC voltage to the arc chamber wall, so that the electrons emitted by the cathode are attracted to the arc chamber wall. During the electron movement, they collide with the doping element molecules in the arc chamber to generate different types of positively charged ions. The required doping ions are selected through the magnetic deflection device, and then the ions are guided and doped into the wafer. However, the ion generation efficiency of the ion implanter in the prior art is low, the electron travel process in the arc chamber is short, and the effective collision probability with the doping element molecules is low, which leads to less doping ions and low productivity; secondly, with the increase of working time, the filament and cathode will be worn out and need to be replaced regularly. During the normal working cycle, their performance will also change over time, thereby affecting the stability of the arc chamber in generating doped ions. In order to ensure the stability of the arc chamber operation, the accuracy and stability of the output voltage and current parameters of the filament power supply, cathode power supply and arc power supply are also very important. Utility Model Content

[0004] The utility model aims to overcome the deficiencies of the prior art and provide an arc chamber power supply control system for an ion source of an ion implanter to solve the above problems.

[0005] The purpose of this utility model is achieved through the following technical solutions:

[0006] An arc chamber power supply control system of an ion source of an ion implanter comprises an arc chamber, a power supply device, and a filament and a cathode arranged at one end of the arc chamber, the cathode is arranged around the filament, and source magnetic devices for changing the electron travel path are also arranged outside the two ends of the arc chamber. The power supply device comprises:

[0007] A filament power supply, the positive and negative electrodes of which are respectively coupled to the two ends of the filament, is used to heat the filament, and a resistor R1 is connected in parallel between the current monitoring port at the output end of the filament power supply and the common end;

[0008] A cathode power supply, the positive and negative electrodes of which are respectively coupled to the cathode and one end of the filament, for applying a forward bias DC voltage of up to several hundred volts relative to the filament, and a resistor R2 is connected in parallel between the current monitoring port at the output end of the cathode power supply and the common end;

[0009] The arc power supply has positive and negative electrodes coupled to the arc chamber wall and the cathode respectively, providing the arc chamber wall with a forward bias DC voltage of hundreds of volts relative to the cathode, and a resistor R3 is connected in parallel between the voltage output positive electrode and the voltage output negative electrode at the output end of the arc power supply.

[0010] In the above utility model, further, a cathode is arranged at the other end of the arc chamber for extending the path of electron travel.

[0011] In the above utility model, further, the filament power supply provides a DC voltage of 0 to 7.5V and a current of 0 to 60A for the filament.

[0012] In the above utility model, further, the cathode power supply provides a bias DC voltage of 0 to 600V and a current of 0 to 1.6A for the cathode.

[0013] In the above utility model, further, the arc power supply provides a bias DC voltage of 0 to 150 V and a current of 0 to 10 A, which is higher than the cathode voltage, to the arc chamber wall of the arc chamber.

[0014] In the above utility model, further, the resistors R1, R2, and R3 are all metal film resistors with an accuracy of 0.1%, the resistance value of the resistor R1 is 15KΩ, the resistance value of the resistor R2 is 10KΩ, and the resistance value of the resistor R3 is 4.99KΩ.

[0015] The beneficial effects of the utility model are:

[0016] The utility model uses a source magnetic device to change the path of electrons, so that the electrons travel in a spiral manner in the arc chamber, which increases the probability of collision between the electrons and the doping gas molecules. At the same time, the three resistors R1, R2 and R3 respectively connected in parallel on the power supply device can effectively improve the power supply performance, that is, improve the stability of the output voltage and current of each DC power supply, reduce the voltage and current fluctuations caused by load changes, thereby more accurately controlling the ionization process of the ion source arc chamber, meeting the ion implantation process requirements of chip manufacturing, improving the overall performance of the ion implanter, shortening the process adjustment and equipment debugging period, and improving the productivity and product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the arc chamber structure and power supply configuration of the ion source of the utility model;

[0018] Figure 2 This is a schematic diagram of the configuration of the resistor module at the output end of the arc chamber power supply of the ion source of the utility model;

[0019] Figure 3 This is a schematic diagram of the resistor configuration at the output end of the power supply of the utility model.

[0020] In the figure, 1-arc chamber, 2-filament, 3-cathode, 4-cathode counter, 5-source magnetic device, 6-filament power supply, 7-cathode power supply, 8-arc power supply. DETAILED DESCRIPTION

[0021] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0022] Please refer to the attached Figure 1 As shown, an arc chamber power supply control system of an ion source of an ion implanter comprises an arc chamber 1, a power supply device, and a filament 2 and a cathode 3 arranged at one end of the arc chamber 1. The cathode 3 is arranged around the filament 2. A source magnetic device 5 for changing the electron travel path is also arranged on the outer sides of both ends of the arc chamber 1. The source magnetic device 5 forms an accelerating electric field from top to bottom in the arc chamber 1, and the electrons emitted by the cathode 3 move from the cathode 3 to the surrounding arc chamber 1 wall. When the emission direction of the electrons is different from the direction of the accelerating electric field, the electrons will move in a spiral manner in the arc chamber 1, thereby increasing the probability of collision between the electrons and the doping gas molecules;

[0023] In this embodiment, preferably, a counter cathode 4 is further configured at the other end of the arc chamber 1 to extend the path of electron travel; specifically, after the cathode 3 emits electrons, a portion of the electrons reach the counter cathode 4, the counter cathode 4 is negatively charged, and the subsequent electrons reaching the counter cathode 4 are repelled back to the middle of the arc chamber 1 and continue to travel in a spiral manner, thereby extending the path of the electron travel; under the joint action of the source magnetic device 5 and the counter cathode 4, the travel distance of the electrons in the arc chamber 1 is greatly increased, thereby improving the ionization efficiency;

[0024] Please refer to the attached Figure 1 -Attached Figure 3 As shown, the power supply device includes:

[0025] The positive and negative electrodes of the filament power supply 6 are respectively coupled to the two ends of the filament 2. The filament power supply 6 provides sufficient current for heating the filament 2, and can provide a DC voltage of 0 to 7.5V and a current of 0 to 60A for the filament 2. When the filament 2 reaches a sufficiently high temperature, the filament 2 begins to emit electrons, and a resistor R1 is connected in parallel between the current monitoring port at the power output end of the filament 2 and the common end. Specifically, the electron emission rate of the filament 2 can be changed by changing the current of the filament power supply 6, so that the electron emission rate tends to be stable;

[0026] The cathode power supply 7, whose positive and negative electrodes are respectively coupled to the cathode 3 and one end of the filament 2, is used to apply a forward bias DC voltage of up to several hundred volts relative to the filament 2, and can provide a bias DC voltage of 0 to 600V and a current of 0 to 1.6A for the cathode 3. The forward voltage of up to 600V can make the electrons emitted by the filament 2 obtain an energy of up to 600 electron volts. The cathode 3 is heated and emits electrons under the bombardment of high-energy electrons. These high-energy electrons continuously bombard the cathode 3, causing the cathode 3 to heat up until the cathode 3 emits electrons. The stability and precise regulation of the cathode operation are sensitive to the current. Therefore, a resistor R2 is connected in parallel between the current monitoring port at the output end of the cathode power supply 7 and the common end;

[0027] The arc power supply 8 has positive and negative poles coupled to the arc chamber wall and the cathode 3 respectively, providing the arc chamber wall with a forward bias DC voltage of hundreds of volts relative to the cathode 3, and the arc power supply 8 provides the arc chamber wall of the arc chamber 1 with a bias DC voltage of 0 to 150V and a current of 0 to 10A, which are higher than the voltage of the cathode 3; in the process of electron movement, the electrons collide with the doping element molecules in the arc chamber 1 to generate different types of positively charged ions, and the required doping ions are selected through the magnetic deflection device; and a resistor R3 is connected in parallel between the voltage output positive pole and the voltage output negative pole at the output end of the arc power supply 8, which can better improve the power supply performance.

[0028] When the arc chamber 1 establishes the arc starting process, a servo loop begins to control the heating current of the filament 2, the emission of electrons from the cathode 3 and the ionization rate. The servo loop ensures that the arc current is maintained at the parameter value selected by the user and is not affected by changes in the current of the filament 2 and the pressure of the doping source gas, thereby ensuring the accuracy and stability of the output voltage and current parameters of the filament power supply 6, cathode power supply 7 and arc power supply 8, thereby being able to more accurately control the ionization process of the ion source arc chamber 1, meet the ion implantation process requirements of chip manufacturing, and improve the overall performance of the ion implantation machine.

[0029] In the above embodiment, preferably, the resistors R1, R2, and R3 are all metal film resistors with an accuracy of 0.1%, the resistance value of the resistor R1 is 15KΩ, the resistance value of the resistor R2 is 10KΩ, and the resistance value of the resistor R3 is 4.99KΩ.

[0030] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0031] The above-mentioned embodiments only express the specific implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the utility model. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model.

Claims

1. An arc chamber power supply control system for an ion source of an ion implanter, characterized in that: The invention comprises an arc chamber (1), a power supply device, and a filament (2) and a cathode (3) arranged at one end of the arc chamber (1); the cathode (3) is arranged around the filament (2); and source magnetic devices (5) for changing the path of electrons are also arranged outside both ends of the arc chamber (1); the power supply device comprises: A filament power supply (6), the positive and negative electrodes of which are respectively coupled to the two ends of the filament (2) for heating the filament (2), and a resistor R1 is connected in parallel between the current monitoring port at the output end of the filament power supply (6) and the common end; A cathode power supply (7), the positive and negative electrodes of which are respectively coupled to the cathode (3) and one end of the filament, for applying a forward bias DC voltage of up to several hundred volts relative to the filament (2), and a resistor R2 is connected in parallel between a current monitoring port at the output end of the cathode power supply (7) and a common end; The positive and negative electrodes of the arc power supply (8) are respectively coupled to the arc chamber wall and the cathode, providing the arc chamber wall with a forward bias DC voltage of hundreds of volts relative to the cathode (3), and a resistor R3 is connected in parallel between the voltage output positive electrode and the voltage output negative electrode at the output end of the arc power supply (8).

2. The arc chamber power supply control system of an ion source of an ion implanter according to claim 1, characterized in that: A counter cathode (4) is also arranged at the other end of the arc chamber to extend the path for electrons to travel.

3. The arc chamber power supply control system of an ion source of an ion implanter according to claim 1, characterized in that: The filament power supply (6) provides a direct current voltage of 0 to 7.5 V and a current of 0 to 60 A for the filament (2).

4. The arc chamber power supply control system of an ion source of an ion implanter according to claim 1, characterized in that: The cathode power supply (7) provides a bias DC voltage of 0 to 600 V and a current of 0 to 1.6 A to the cathode (3).

5. The arc chamber power supply control system of an ion source of an ion implanter according to claim 1, characterized in that: The arc power supply (8) provides a bias DC voltage of 0 to 150 V and a current of 0 to 10 A, which is higher than the cathode voltage, to the arc chamber wall of the arc chamber (1).

6. The arc chamber power supply control system of an ion source of an ion implanter according to claim 1, characterized in that: The resistors R1 , R2 , and R3 are all metal film resistors with a precision of 0.1%. The resistance value of the resistor R1 is 15KΩ, the resistance value of the resistor R2 is 10KΩ, and the resistance value of the resistor R3 is 4.99KΩ.

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