JPH0211762A - Method of implanting middle and high energy into surface working vessel - Google Patents

Abstract

PURPOSE:To easily implant the ion species of high energy at a uniform concn. to a working material by generating or introducing plasma in a surface working vessel and impressing the pulses of AC/DC discharge voltages to an insulating electrode enclosing the working material. CONSTITUTION:The working material 2 mounted to a material supporting base 3 in the surface working vessel 1 consisting of a vacuum vessel having a discharge pump 7 is heated up to a prescribed temp. The plasma is introduced via a bias power source 13 from a plasma source 12 into this vessel 1. A gaseous plasma source is otherwise introduced into the vessel from a gas port 8 and a filament grid 5 is heated to generate the plasma. Further, the bias voltage is impressed between the filament grid 5 and the working material 2 by a power source 15. Further, an AC/DC discharge power source 14 is intermittently and impulsively operated to impress the discharge voltage to the insulating electrode 4 of a cap-like shape made of a net enclosing the working material 2 to the extent of averting the induction of the arc discharge. The required ion species are easily implanted by high energy to the working material 2 in the arbitrary period of the surface working without using an accelerator.

Description

[Detailed description of the invention]

``Purpose of the Invention'' When modifying the surface of a material or improving the adhesion of a thin film by ion implantation, ion beam mixing, dynamic mixing, etc., currently, ion implantation is performed using an accelerator, and surface processing is performed using various surface processing devices. As this process is carried out using multiple independent devices, the material to be processed must be reloaded into the device each time.As a result, the material to be processed is subjected to unnecessary repeated heating and cooling, and is exposed to air. The ideal engineering surface modification was hindered due to surface contamination. Furthermore, in a processing process that uses a plurality of devices including large-sized devices, it is difficult to fundamentally solve technical, time-consuming, and economical problems, which poses an obstacle to industrial application. In fact, (a) without using a so-called accelerator, (b) in a vacuum vessel for surface processing, (c) without exposing the material to air during processing, (d) before, during, or after surface processing. , at any time after the treatment, (e) without causing arc discharge, (f) the required ion species, (g) several k e V - several tens of
The direct purpose of the invention was to be able to (h) inject only the necessary fluence into the processed material with a high energy of 0 ke V. ``Application field'' Metals, non-metals, organic materials, amorphous, etc. - Improvement of surface hardness, toughness, melting point, corrosion, wear resistance, etc. of general industrial materials, materials for electronic materials and optical communications for advanced technology fields, medical care This will provide new manufacturing methods for the development of industrial materials and the creation of new materials at the atomic level. ``Prior art'' No conventional technology has yet been developed that can achieve the actual purpose, although it could be carried out using only ion implantation using an accelerator. In addition, if the ion bracing method is used, several k
``Problems to be solved by the invention'' that could be achieved with only ion implantation below eV By performing ion implantation using an accelerator and then applying a surface nitriding method, it is possible to solve problems that would not be possible with conventional nitriding methods. The present inventor recently discovered that it has become possible to nitride aluminum and that the activation energy for forming nitrogen compounds has been significantly reduced (Text L2). Because the current and irradiation area are small,
If the processing IA material is large, the irradiation time will be long and the beam
Dimensions must be moved or materials must be rotated, and
In that case, non-uniformity occurs in the surface distribution of the ion dose. Furthermore, due to the linearity of the beam at the ion irradiation part, ions can be applied to abrasive materials whose structure is complex! ] It is impossible in principle to violate the law. Therefore, even for materials with complex structures and large irradiation surfaces, high-energy ion implantation can be performed all at once without moving once the material is fixed, and nitriding can be performed in the same vacuum chamber. In order for the above-mentioned discoveries and ion beam mixing to become more common, it is important to devise a device configuration that can perform surface processing such as surface processing and thin film formation. ``Structure of the Invention'' The actual embodiment is shown in Fig. 1, in which there are 6 exhaust pumps (7
) are electrically insulated and connected to the surface-treated container (1), and a net hat-shaped or cylindrical insulated electrode (4), each electrically insulated by an insulating material (6), and a filament grid ( 5) Furthermore, in addition to providing a material support stand (3) on which the processed material (2) is directly fixed in the center, and current introduction terminals for various power sources, necessary gases are introduced during ion implantation or ground surface processing. a gas port (8) and an oven (9, 10) for vaporizing solid or liquid raw materials;
), in which a plasma source (12) for supplying ion raw material as plasma is provided inside and outside the container, each electrically insulated from the earth. As a power source, an AC/DC discharge voltage 11iii (+4) for accelerating and implanting ions is connected between the insulated electrode (4) and the processing material (2) as a cathode, and a grid bias power source (15) is connected. Between the material support table (3) and the filament grid (5), a plasma power supply (not shown in the figure) is connected to the plasma source, a bias power supply (13) is installed for diffusing the plasma generated by the plasma source, and a processing material (2) is connected to the material support table (3). ) and a power source (not shown) to heat the filament grid (5).
A coil (16) and a power source (not shown) for superimposing a weak magnetic field are provided on the inner periphery of the insulated electrode. In the ion implantation process, the material to be processed (2) is fixed to the material support (3), the surface processing container (1) is evacuated, the filament grid (5) is heated, and the filament grid (5) is heated to a voltage of several V-several lower than the material to be processed. Apply a negative bias of kV. Then, after introducing or generating the implanted ion raw material gas into the same container, or introducing the same waste as plasma (however,
At this time, the filament grid does not need to be heated)
, the temperature of the material to be processed is raised appropriately using a heater (11). Then, after suppressing the gas pressure and discharge voltage and setting a short pulse time width to an extent that does not induce arc discharge, the AC/DC discharge power source (5) is operated intermittently in pulses to generate plasma (ion (when the raw material is introduced in a gaseous state) and ion implantation is performed. The ion fluence is controlled by adjusting the number of pulses, the gas pressure, etc. In addition, in the case of processing materials that are likely to induce arc discharge, the coil (1G) is activated to suppress the occurrence of arcing. Various surface treatments such as forming a thin film or nitriding layer can be performed by operations independent of the ion implantation mentioned above while keeping the processed material in its original state.For example, when performing nitriding treatment,
After heating the nitriding material (2) to the processing temperature using the heater (II) and introducing a predetermined nitrogen-hydrogen mixed gas,
Claw discharge occurs when the nitride material (2) and the insulated electrode (4) open,
Alternatively, by generating a high-frequency discharge and submerging the material to be processed at a negative potential with respect to the generated plasma potential, sludge soft nitriding or ion nitriding can be performed.
After generating the same mixed plasma in step 2), turn on the bias power supply (
13) Plasma source nitriding can be performed by applying a negative DC bias to the material to an extent that does not induce arc discharge while using the AC/DC discharge power source (5) for direct current. PVD, CVD, sputtering,
Ion blating involves introducing or generating raw material as gas or steam into the surface processing container (1) from the waste port (8) or oven (9), or introducing the processed material (2) into the surface processing container (1). ) and the insulated electrode (4), an AC/DC discharge power source (
This can be carried out by applying an appropriate bias using 5). Actually, by the above operation,

[Ion implantation]

[Various surface processing methods]... in the same vacuum container,
"Action" refers to the structure of the ion implantation method that can be carried out in arbitrary sequential combinations.Pulsed high voltage between the processed material (2) and the insulated electrode (4). By lowering the gas pressure and making the application time extremely short, plasma can be generated (during gas injection) and ions can be injected into the material at high energy at the same time without inducing arc discharge. A possible effect is produced. In addition, the filament grid (5) emits thermionic electrons when heated, which facilitates plasma generation even when the gas pressure and pulse voltage are lowered. In addition, a negative bias is applied to the processed material. During ion implantation, electrons are supplied to the surface of the processed material, which not only allows efficient ion implantation into insulating materials such as ceramics, but also activates the surface of the material. If the plasma source (12) is used, the ion implantation process including plasma generation can be performed stably even if the ion implantation voltage is lowered, and the ion flux increases, and as a result of constantly enveloping the surface of the processed material with plasma, When ion implantation is performed before, during, or after surface processing of various materials, such as Honjitsu, which has the effect of maintaining or exciting the activated state of atoms on the material surface, ion radiation damage to the material surface and high-density metal interlayers may occur. For example, in ion implantation as a pretreatment for surface nitriding, which will be detailed in the next section, the ion implantation increases the adhesion and adsorption rate of nitrogen ions, atoms, and molecules in the gas phase to the material surface. . In addition, nitrogen taken into the solid phase diffuses at increased speed along dislocations and grain boundaries that are densely distributed on the material surface. In this case, the intermetallic compound is thought to have the effect of changing the potential distribution between the material's constituent atoms and promoting the diffusion of nitrogen ions. It is possible to easily and uniformly implant high-energy, arbitrary ion species to any dose in a surface treatment container, and the material can be easily and uniformly implanted between the ion implantation process and other surface treatment processes. It is now possible to form a high-quality surface-modified layer without causing any air pollution. A specific example is the effect of pre-implantation of nickel, molybdenum, and nitrogen ions in the nitriding process of pure iron and aluminum materials. The implantation made it possible to shorten the nitriding time, improve the nitrided layer thickness, and nitride aluminum (see Sentences 1 and 2, and Figure 2.3). In addition, as an example of using pre-ion implantation as a means of controlling material modification, the thickness of the ε phase and t' phase generated on the steel surface can be selected by adjusting the ion species and implantation dose. or change the
As a result of being able to control the content ratio of aluminum nitride to the base material on the surface of pure aluminum, there was a pre-ion implantation effect that could be applied to the manufacture of electronic devices. In addition, when ion beam mixing is carried out in practice, ion implantation can be applied before, during, or as a post-treatment for forming a thin film, which is more effective in modifying the formed thin film and improving its adhesion. It can also be applied to a new type of composite surface processing method that combines thin film formation, nitriding processing, and ion implantation.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram and electrical wiring diagram of an example of the high-energy ion implantation method in a real surface-treated container, 1) a surface-treated container;
2) Processing material, 3) Material support, 4) Insulated electrode, 5) Filament grid, 6) Insulating material, 7) Exhaust pump, 8
) Gas port, 9.10) Oven, 11) Heater, 1
2) Plasma fi, 13) Bias power supply, +4) AC/DC discharge power supply, 15) Grid bias power supply, 16) Coil. FIG. 2 shows the change in hardness ratio in the depth direction of the pure iron surface subjected to plasma source nitriding treatment at 350 degrees Celsius for 1 hour after pre-ion irradiation, and its dependence on ion species and ion dose. However, the hardness ratio is based on the base material hardness of 1. From Figure 1, it can be seen that ion implantation has the effect of significantly increasing the nitriding reaction. (・) indicates non-ion irradiation, (○), (b), (Δ)
is a nickel ion with an energy of -25KeV and each line J11
E15.5E16, IE17 [ions/cm2] implantation, (■) is 5E1 nitrogen molecule ion at the same energy as above.
Figure 3 shows the change in hardness ratio in the depth direction, the ion species, and Ion dose dependence It was confirmed by AES measurement that the hardened layer shown in Figure 0 was a layer containing 40% AIN, and it was demonstrated that ion implantation enables nitriding of aluminum by surface nitriding. (・) is non-ion irradiation, (○) is molybdenum ion irradiation with 3E15, (
b) Nitrogen molecular ions were implanted at 4E19 [ions/sq.t.] at 25 keV each. Fig. 1. Schematic diagram and electrical wiring diagram of an example of high-Niometry ion implantation method in a real surface processing container Fig. 2. Surface hardness ratio and Dependency of nitrided layer thickness on ion species and ion dose Figure 3: Dependence of ion species and ion dose on surface hardness ratio and nitrided layer thickness of pure aluminum treated by plasma source nitriding method after ion implantation pre-treatment Nitrided layer thickness (11m)

Claims (1)

[Claims] High-energy ion implantation can be performed in a vacuum chamber in which various surface treatments of materials can be performed, in a relatively small volume without using an accelerator, as a pre-, intermediate-, or post-treatment. This relates to an ion implantation method that can be carried out in the same vacuum container, that is, a material support stand (3) with a processing material (2) attached, and an insulated electrode (4), each electrically insulated in the surface processing container (1). ), a filament grid (5), and a plasma source (12), and after the implanted ion raw material is injected as a gas from the gas port (8) or oven (9, 10) or introduced as a plasma, the filament grid (5) is provided. ) to the processed material (2) and the insulated electrode (4), which are connected via the grid bias power supply (15), using the AC/DC discharge power supply (14) to apply a short pulse with the insulated electrode as the anode. An ion implantation method that involves applying high DC voltage intermittently. In addition, when supplying the implanted ion raw material as a gas, the filament grid (5) can be heated with a heater (11), and a coil (16) can be installed to heat the filament grid (5) when the AC/DC discharge power supply (14) is activated. The structure is such that a magnetic field that intersects with the electric field generated inside the insulated electrode can be superimposed. (See Figure 1).