CN223123864U - An ion source implanter with precise control of beam focusing - Google Patents

Abstract

The utility model proposes an ion source implanter with precise control of beam focusing, including an ion beam system and a target platform. The ion beam system includes a gas box, an ion source, a mass analyzer, an accelerating tube and a focusing device connected in sequence. The gas box and the ion source generate an ion beam, which is accelerated by the accelerating tube and injected into the focusing device after the impurity ions are screened out by the mass analyzer. The focusing device is provided with a plurality of focusing structures arranged at intervals. The surface of the focusing device is provided with a plurality of energized columns corresponding to the focusing structure. The focusing structure is electrically connected to the energized columns so that the energization of the focusing structure generates a force on the ion beam. A receiving portion is provided on the target platform, and the receiving portion is aligned with the focusing device. The technical solution of the utility model can flexibly adjust the focus according to the scattering degree of the ion beam, better suppress the scattering phenomenon of the ion beam, and more accurately control the focusing degree of the ion beam.

Description

Ion source implanter capable of accurately controlling beam focusing

Technical Field

The utility model relates to the technical field of ion implantation equipment, in particular to an ion source implanter capable of accurately controlling beam focusing.

Background

The electrical properties of semiconductor devices depend on the impurity concentration of semiconductor doping, and in the semiconductor wafer manufacturing process, to change pure silicon with poor conductivity into a useful semiconductor, a small amount of impurities needs to be added to change the structure and conductivity of the pure silicon, which is called doping, and the current doping technology has two methods, namely a high-temperature thermal diffusion method and an ion implantation method, wherein ion implantation occupies the dominant position.

An ion source implanter is an apparatus for implanting specific types of ions in a wafer, and its basic principle of operation is by accelerating and focusing a beam of ions and implanting them into a target material. In the process of implanting ions, since the ion beam is composed of positive ions, a phenomenon of scattering occurs due to repulsive force during the transmission, and thus a focusing device is required to focus the ion beam.

The existing focusing device usually uses a whole annular focusing ring to electrify to generate an electric field to focus an ion beam, but scattered ions carry inconsistent kinetic energy, scattered speeds and paths are disordered, and the whole electrified focusing ring is at the same electric potential, so that the focusing effect on the ions is limited, the focusing can only be controlled approximately, and a better focusing effect cannot be achieved.

Disclosure of utility model

In order to solve the problems in the background art, the utility model provides an ion source implanter capable of accurately controlling beam focusing, which aims to flexibly adjust focusing according to the scattering degree of an ion beam, better inhibit the scattering phenomenon of the ion beam and control the focusing degree of the ion beam more accurately.

The utility model solves the technical problems by adopting the scheme that the ion source implanter for precisely controlling the focusing of the beam current comprises:

The ion beam system comprises a gas box, an ion source, a mass analyzer, an accelerating tube and a focusing device which are sequentially connected, wherein the gas box and the ion source generate ion beams, impurity ions are screened out by the mass analyzer and are accelerated to be injected into the focusing device by the accelerating tube, a plurality of focusing structures which are arranged at intervals are arranged in the focusing device, a plurality of electrifying columns are arranged on the surface of the focusing device corresponding to the focusing structures, and the focusing structures are electrically connected with the electrifying columns so that the focusing structures are electrified to generate acting force on the ion beams;

the target table is provided with a containing part, and the containing part is aligned with the focusing device.

In an embodiment of the utility model, the focusing device is internally provided with an ion channel, an electrode cavity is hollow in the inner part of the side wall of the focusing device, and a plurality of focusing structures are arranged in the electrode cavity at intervals along the ion channel.

In one embodiment of the present utility model, the focusing structure includes at least two electrodes symmetrically disposed with respect to the ion channel.

In an embodiment of the present utility model, the electrodes of each two adjacent focusing structures are disposed in a staggered manner.

In one embodiment of the present utility model, the inner diameter of the ion channel gradually decreases along the direction of movement of the ion beam.

In an embodiment of the utility model, a side wall of the ion channel is coated with a graphite protective layer.

In summary, the utility model has the beneficial effects that the focusing device is arranged at the outlet of the accelerating tube, the focusing device is internally provided with the plurality of focusing structures which are arranged at intervals, the focusing structures are composed of at least two opposite electrodes, the electrodes can generate acting force on the ion beam after being electrified with voltage to inhibit scattered ions, the voltage on different electrodes is regulated according to the scattering condition of the ion beam, the best effect of inhibiting the ion scattering can be achieved, and the focal length of the ion beam can be regulated. The technical scheme of the utility model can flexibly adjust the focusing according to the scattering degree of the ion beam, better inhibit the scattering phenomenon of the ion beam and control the focusing degree of the ion beam more accurately.

The foregoing description is only an overview of the technical solution of the present utility model, and may be implemented according to the content of the specification in order to make the technical means of the present utility model more clearly understood, and in order to make the above and other objects, features and advantages of the present utility model more clearly understood, the following specific preferred embodiment is given by way of the following detailed description in conjunction with the accompanying drawings.

Drawings

Fig. 1 is a schematic structural view of the present embodiment;

Fig. 2 is a cross-sectional view of the focusing apparatus of the present embodiment;

Fig. 3 is a schematic layout diagram of a focusing structure in this embodiment.

The ion beam system comprises a beam source 1, a gas box 3, an ion source 4, a mass analyzer 5, an accelerating tube 6, a focusing device 61, a focusing structure 62, a power-on column 63, an ion channel 64, an electrode cavity 65, an electrode 66, a graphite protective layer 7, a target table 71 and a containing part.

Detailed Description

In order that the utility model may be more readily understood, a further description of the utility model will be rendered by reference to specific embodiments that are illustrated in the appended drawings.

It should be noted that, as used herein, the terms "center," "upper," "lower," "front," "rear," "left," "right," "inner," "outer," and the like indicate an orientation or a positional relationship based on that shown in the drawings, and are merely for convenience of description and to simplify the description, and do not indicate or imply that the apparatus or element in question must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the utility model. Unless otherwise indicated, the meaning of "a plurality" is two or more.

Unless specifically stated or limited otherwise, the terms "mounted," "connected," "coupled," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, directly connected, or indirectly connected via an intervening medium, or may be in communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art in a specific case.

As shown in fig. 1 to 3, the utility model provides an ion source 3 implanter for precisely controlling beam focusing, which comprises an ion beam system 1 and a target table 7, wherein the ion beam system 1 comprises a gas box 2, an ion source 3, a mass analyzer 4, an accelerating tube 5 and a focusing device 6 which are sequentially connected, the gas box 2 and the ion source 3 generate ion beams, the accelerating tube 5 is used for accelerating and injecting the ion beams into the focusing device 6 after screening impurity ions by the mass analyzer 4, a plurality of focusing structures 61 which are arranged at intervals are arranged in the focusing device 6, a plurality of electrifying columns 62 are arranged on the surface of the focusing device 6 corresponding to the focusing structures 61, the focusing structures 61 are electrically connected with the electrifying columns 62 so as to electrify the focusing structures 61 to generate acting force on the ion beams, a containing part 71 is arranged on the target table 7, and the containing part 71 is aligned with the focusing device 6.

It will be appreciated that the configuration of the gas box 2, the ion source 3, the mass analyzer 4 and the accelerating tube 5 is the prior art, and only a brief description is made here, the gas box 2 is used for providing the ion source 3 with the gas to be ionized, the hot electrons generated in the ion source 3 bombard the gas molecules under the action of the electric field to ionize the gas molecules, all positively charged ions are led out from a slit by the positive pressure repulsion of the anode of the ion source 3, at this time, electrons in the plasma are repelled by the cathode to be blocked, thereby forming an ion beam composed of positive ions, the hot electrons bombard the impurity source gas molecules to generate a plurality of ions, the mass-to-charge ratio of each ion is different, the movement orbit of the ions can be different under the action of the magnetic force when passing through the mass analyzer 4, the required impurity ions can be separated from the mixed ion beam, in order to enable the ions to obtain larger energy to meet the injection requirement, the positive ions are further accelerated by the high voltage of the accelerating tube 5 through a series of electrodes, the negative voltage on the electrodes are formed by a series of medium isolated negative voltage, and the ions are sequentially increased, and the positive voltage on the electrodes are sequentially increased, the negative voltage is higher, and the total kinetic energy of the ions are higher when the ions are moved to the negative voltage.

The ion beam enters the focusing device 6 after leaving the accelerator, the focusing device 6 is provided with a channel for allowing ions to flow, a plurality of focusing structures 61 are arranged inside the focusing device 6 along the channel, acting force is generated on the ion beam moving along the channel after voltage is applied to the focusing structures 61, so that the focusing effect is achieved, the directions of the acting forces generated by the plurality of focusing structures 61 on the ion beam are inconsistent, the voltage on different focusing structures 61 can be adjusted according to the scattering condition of the ion beam, so that the best effect of inhibiting the ion scattering is achieved, and the focal length of the ion beam can be adjusted.

The target table 7 is used for placing a wafer to be doped, the target table 7 can be externally connected with a servo motor so as to facilitate lifting, rotating and the like, a containing part 71 is arranged on the target table 7, the size of the containing part 71 is matched with the size of the wafer, the wafer is placed in the containing part 71, and the containing part 71 is aligned with the outlet of the focusing device 6 so as to facilitate ion beam emitted from the focusing device 6 to be injected into the wafer.

As shown in fig. 2, in an embodiment of the present application, the focusing device 6 has an ion channel 63 therein, and an electrode cavity 64 is hollow in the sidewall of the focusing device 6, and a plurality of focusing structures 61 are disposed in the electrode cavity 64 at intervals along the ion channel 63.

It will be appreciated that one end of the ion channel 63 is connected to the outlet of the accelerating tube 5, the ion beam is injected into the focusing device 6 from the accelerating tube 5 and moves along the ion channel 63, the side wall of the ion channel 63 is hollow, a plurality of cavities named electrode cavities 64 are formed in the focusing structure 61 along the moving direction of the ion beam, when the ion beam moves in the ion channel 63, the focusing structure 61 is electrified to restrain scattered ions, and meanwhile, the voltage on different focusing structures 61 can be adjusted according to the scattering condition of the ions so as to achieve the best focusing effect, and the focal length of the ion beam can be adjusted.

As shown in fig. 2 to 3, in an embodiment of the present application, the focusing structure 61 includes at least two electrodes 65 symmetrically disposed with respect to the ion channel 63.

It will be appreciated that the electrodes 65 are symmetrically disposed with respect to the ion channel 63, and the two electrodes 65 are connected in series, and after the electrode 65 is energized by the energizing post 62, the two electrodes 65 apply forces to the ion beam from opposite directions, so as to inhibit the scattering of ions, and control the focusing of the ion beam, and compared with the conventional manner of controlling the focusing by using the whole focusing ring, the use of the symmetrically disposed two electrodes 65 can inhibit the scattering of ions in a fixed direction more precisely, and the arrangement of the plurality of electrodes 65 toward different focusing structures 61 can flexibly adjust the focal length of the ion beam, and meanwhile, the inhibition effect on scattered ions is better.

As shown in fig. 2 to 3, in an embodiment of the present application, the electrodes 65 of each two adjacent focusing structures 61 are disposed in a staggered manner.

It can be appreciated that the electrode 65 is arranged in a staggered manner to inhibit ions scattered in different directions in the ion beam, and according to the scattering condition of the ion beam, the voltage of the electrode 65 on different focusing structures 61 can be adjusted to achieve the best effect of inhibiting ion scattering, and the focal length of the ion beam can be adjusted.

As shown in fig. 2, in one embodiment of the present application, the inner diameter of the ion channel 63 gradually decreases in the direction of beam movement.

It will be appreciated that the ion channel 63 has a tapered structure with a uniformly shrinking inner diameter, the larger inner diameter end is the end into which the ion beam enters, the smaller inner diameter end is the end from which the ion beam exits, the closer the focusing structure 61 near the exit end is to the ion beam in the ion channel 63, the stronger the force applied to the ion beam, and by the above arrangement, the focusing of the ion beam is controlled so that the closer it is to the outlet of the ion channel 63, the more concentrated it is.

As shown in fig. 2, in one embodiment of the present application, the side walls of the ion channel 63 are coated with a graphite protective layer 66.

It will be appreciated that since a very small portion of the ions may carry a relatively large kinetic energy to impinge on the inner wall of the ion channel 63, metal contamination may have long been caused, and even the inner wall may be broken down, damaging the electrode 65, and the provision of the graphite shield may protect the inner wall of the ion channel 63 from metal contamination.

In summary, the beneficial effects of this embodiment are that, by arranging the focusing device 6 at the outlet of the accelerating tube 5, and arranging a plurality of focusing structures 61 in the focusing device 6 at intervals, the focusing structures 61 are composed of at least two opposite electrodes 65, the electrodes 65 can generate acting force on the ion beam after being electrified to suppress scattered ions, and the voltage on different electrodes 65 can be adjusted according to the scattering condition of the ion beam, so that the best effect of suppressing ion scattering can be achieved, and the focal length of the ion beam can be adjusted. The technical scheme of the utility model can flexibly adjust the focusing according to the scattering degree of the ion beam, better inhibit the scattering phenomenon of the ion beam and control the focusing degree of the ion beam more accurately.

The above examples are only preferred embodiments of the present utility model, and the scope of the present utility model is not limited thereto, but any insubstantial changes and modifications made by those skilled in the art based on the present utility model are included in the scope of the present utility model.

Claims (6)

1. The ion source implanter is characterized by comprising an ion beam system (1), wherein the ion beam system (1) comprises a gas box (2), an ion source (3), a mass analyzer (4), an accelerating tube (5) and a focusing device (6) which are sequentially connected, the gas box (2) and the ion source (3) generate ion beams, impurity ions are screened out by the mass analyzer (4) and then are accelerated by the accelerating tube (5) to be injected into the focusing device (6), a plurality of focusing structures (61) which are distributed at intervals are arranged in the focusing device (6), a plurality of energizing columns (62) are arranged on the surface of the focusing device (6) corresponding to the focusing structures (61), and the focusing structures (61) are electrically connected with the energizing columns (62) so that the focusing structures (61) are energized to generate acting force on the ion beams;

The target table (7), be equipped with accommodation portion (71) on target table (7), accommodation portion (71) aim at focusing device (6).

2. The ion source implanter according to claim 1, wherein the focusing device (6) has an ion channel (63) therein, an electrode cavity (64) is formed in a hollow manner in a sidewall of the focusing device (6), and a plurality of focusing structures (61) are disposed in the electrode cavity (64) at intervals along the ion channel (63).

3. The ion source implanter of precisely controlled beam focusing of claim 2, wherein the focusing structure (61) comprises at least two electrodes (65) symmetrically disposed with respect to the ion channel (63).

4. An ion source implanter for precisely controlling beam focusing according to claim 3, wherein the electrodes (65) of each adjacent two of the focusing structures (61) are offset.

5. The ion source implanter of claim 4, wherein the ion channel (63) has an inner diameter that gradually decreases in a direction of beam movement.

6. The ion source implanter of claim 5, wherein a sidewall of the ion channel (63) is coated with a graphite protection layer (66).