DD286375A5 - ARC DISCHARGE EVAPORATOR WITH SEVERAL EVAPORATOR TILES - Google Patents

Abstract

The invention relates to an arc discharge evaporator with a plurality of evaporator crucibles, in particular for the production of plasma-deposited mixed or multilayers. The evaporator can be advantageously used wherever two or more vaporizable substances are to be evaporated in parallel or in succession. Deposition on the substrate may be reactive for any or all of the evaporation materials. The invention has for its object to provide an arc discharge evaporator with several evaporator crucibles, with which the evaporation materials used can be evaporated individually or together and with variable Mischungsverhaeltnis. According to the invention, the object is achieved by the arc discharge evaporator having one cathode and a plurality of anodic evaporation crucibles, wherein the evaporator crucibles are insulated from each other, each having a separate current supply, and are arranged together within the effective range of a common magnet system for arc steering. The power supplies are each connected to controllable power sources. Fig. 1 {arc discharge evaporator; a cathode; several anodic vaporizer crucibles; separate controllable power supplies; common magnet system; Mixed and multilayers, reactive}

Description

For this 2 pages drawings

Field of application of the invention

The invention relates to an arc discharge evaporator with a plurality of evaporator crucibles, in particular for producing plasma-assisted mixed or multilayers. The evaporator can be used advantageously wherever two or more vaporizable substances are to be evaporated in parallel or successively. The deposition on the substrate can be reactive for one or all of the evaporation materials.

Characteristic of the known state of the art The arc discharge evaporators have acquired particular importance in plasma-assisted layer production. That's it

irrelevant, whether a thermionic or Hohlkatode is used. With Jen arc discharge evaporator, the effective evaporation of the evaporation material is combined in a very advantageous manner with the simultaneous plasma generation.

This avoids expensive additional plasma generating devices. Ancestors are typically the same

substrates coated UUF negative potential relative to the anode and the evaporator crucible teilweiseionisierte in plasma evaporating material and / or reactive and carrier gas with high energy on ^ci: extracted e substrate surface.

This mechanism results in high bond strengths of the deposited high density layer in the presence of reactive gas

to intense reactions of the materials involved. In grossor width was using this technology the

Hard Coating vo ^r wear surfaces for tools or construction Share with TiN, TiC and other Hard materials introduced into practice. In addition, the technology will also be beneficial for hard decorative coatings

used. Specifically, the gold-colored titanium nitride has wide application in the coating of wrist watch case,

Visual aids, writing utensils and jewelery found. In all these cases, only one metal (Ti, Ta, Hf, Va, Cr, and the like) must be vaporized while the second reaction medium is gas

is supplied.

More recently, it has become increasingly necessary to evaporate at least two materials. This is z. B. required if on

because of the "true" gold tone, the TiN layer should still be vapor-deposited on a thin layer of gold or real

Mixed shich; sn, z. B. Ti _x Al _y , to be made of solid materials. According to the prior art, this is usually

each used a second evaporator. US Pat. No. 4,415,421 discloses a device for producing a TiN-Au layer in which the Ti is vaporized by means of arc discharge. This device also generates the required plasma. The gold is sputtered by sputter source. If necessary, additional sputter sources are used for other materials such as Cu or Pde. This solution is very complicated by Jie simple addition of steam sources and requires a high proportion of

Working space. In mixed layers, it may be detrimental to the homogeneity of the layer when the various vapor streams are out

get different directions on the substrate.

DD-WP 232513 describes an arc discharge evaporator in which, after the initial ignition of the discharge

between a cathode and an anodic crucible the further discharge burns between two vaporizer crucibles, which as

Electrodes of alternating polarity are connected. It also indicates the possibility, depending on a

variable duty cycle and / or the amounts of energy from the two crucibles to vaporize different amounts of different material. The disadvantage of this device is the relatively complicated control. The further evaporates always from the instant c-! S cathode working pot material or is sputtered off, which leads to the fact that no pure layers of lying at anodic potential material can be produced. As always only one of the two

Evaporator crucible as anode material evaporates, are also no pure mixed layers by means of simultaneous evaporation

Both materials can be produced.

In the DD-WP 263423 it is proposed that in the outer plasma of an arc discharge evaporator an additional

To arrange anodic crucible and to extract on this electron from the plasma with such energy and current density that evaporates there evaporating matsrial. This solution has proven to be relatively good for the flash-like evaporation of small amounts of gold for deposition on a TiN layer.

However, the solution is for low evaporation rates of evaporative material with low evaporation temperature

limited. Thus, it can not be used for many tasks for the production of mixed and multilayers.

In the known high-energy electron beam evaporators are various solutions for multi-pot evaporator

and known by jumping jets. However, the transfer of these solutions to the technique of arc discharge is not possible because the high current arc discharge can not be sufficiently bundled and steered.

Object of the invention

The invention pursues the goal of producing high-quality mixed and multiple layers plasma-assisted and with minimal technical and economic effort.

Explanation of the essence of the invention

The invention has the object to provide an arc discharge evaporator with several evaporator crucibles, with which the evaporation materials used can be vaporized individually or together and with a variable mixing ratio.

According to the invention the object is achieved in that the arc discharge evaporator comprises a cathode and a plurality of anodic evaporator, wherein the evaporator crucible are insulated from each other, each having a separate power supply, and are arranged together within the effective range of a common magnet system for arc steering. The power supply lines are each connected to controllable current sources. The various vaporizer crucibles are advantageously arranged at a small distance from each other around the center of the electron flow of the Rogenentladung around.

When all vaporizer crucibles are at the same anode potential during operation of the vaporizer, the arc current is also relatively evenly distributed to all crucibles and the vaporizing materials are vaporized according to their vaporization characteristics. If only one crucible is at anode potential and the other crucibles are at floating potential, then the arc discharge only burns against the one crucible with anode potential and only this evaporation material is vaporized. At different potentials at the individual vaporizer crucibles, the electron current splits accordingly. It is only important that the individual evaporator crucibles are still in the effective range of the common magnet system for sheet steering. Immediately übar the crucibles of the arc current is then influenced by the potentials. This allows the compact multi-pot evaporator in any way the evaporation of a material, several materials in succession and several materials in any mixing ratios simultaneously. The type of cathode used for the evaporator is of no particular importance. Glow cathode and hollow cathode are both well used.

It has proven to be advantageous to install simple vapor barriers between the individual evaporator crucibles so that the individual evaporation materials do not already influence the crucible and thus the individual materials are contaminated. However, such vapor barriers must not hinder the flow of electrons from the cathode to the anodic crucibles. Depending on the field of use of the evaporator, the digestion crucibles may be the same or specialized for the materials. For example, an evaporator crucible can be regularly formed as a crucible and other ship-like, even with. Nachfütterungseinrichtung. The Nachfütterungshinrichtung must be fully isolated so that the sheet does not burn against them.

The classification of the evaporator in the process is carried out in a known manner. So the evaporation can be done by quantity or time control. If necessary, however, it is also possible to use in situ controllers with measuring means for each individual vapor component. If necessary, reactive atmospheres, in particular η it N ₂ , C _x or O; be used.

embodiment

The invention will be explained in more detail below with reference to two examples

 The accompanying drawings show in

1: a two-crucible evaporator according to Example I and

2 shows an evaporator with Nachfütterungseinrichtung for a material according to Example II.

Example I

Example I describes a two-pot evaporator. The accompanying drawing shows in Fig. 1, the Kompt ktanordnung of an evaporator crucible 1 without lining of the crucible and an evaporator crucible 2 with a crucible insert 3 on graphite. Both evaporator crucibles 1 and 2 are isolated by means of ceramic insulator 4 against each other, but mounted as a whole block. Immediately associated with this anode assembly is a common magnetic system consisting of a magnetic coil 5 and two lateral magnetic plates 6, which generate a longistudinales magnetic field over the two evaporator crucibles 1 and 2. Laterally and structurally separate from the anode assembly a hollow cathode 7 is arranged. When the arc discharge is ignited in a known manner, the electron current enters the region of influence of the magnetic field and is directed by it onto the anode crucibles 1 and / or 2. As a further means for guiding and steering the electron flow, a common aperture 8 is isolated above the evaporator crucibles 1 and 2. Due to its floating potential, the diaphragm 8 focuses the electron flow through the openings directly onto the evaporation material lying in the evaporator crucible 1 or 2. This ensures in particular that the electron beam does not burn against other parts of the anode than the crucible. Immediately associated with the aperture 8, a vapor barrier 9 is provided so that the individual vapor streams can not reach the other crucible and lead there to undesirable deposits.

The potential supply to the anodic evaporator crucibles 1 and 2 is carried out separately via the Zuführungsn 11 and 12. The representation of the cooling water supply was omitted for clarity. The following describes the use of this evaporator for the preparation of a Ti-Cu mixed layer in the ratio of 5: 1, as it can be used for abrasion-resistant electrical contact surfaces v.erden.

In a known manner, an argon pressure of <1 × 10 ^-3 Pa is controlled in the receiver, after which the arc discharge in the hollow cathode 8 is ignited, the evaporator crucible 1 serving as an anode with the evaporation material titanium Evaporator crucible 2 is adjusted to 50 A. This results in evaporation rates of 0.5 g / min for Ti and 0.1 g / min for Cu. Dioe-deposited Ti-Cu layer is adhesive, dense, dense according to the plasma-assisted deposition Good conductivity and is very homogeneous in itself .. The production with the multi-pot evaporator according to the invention is very inexpensive and easy to control.

By changing the anode currents on the evaporator crucibles, the mixing ratio of the layer can be varied practically from 100: 0 to 0: 100. With the participation of reactive gases in whole or in part, the variability of the producible layer types can be significantly increased.

Example Il In the following, an evaporator according to the invention is described in which an evaporating material is constantly re-fed

becomes. This evaporator is particularly suitable for mixed aluminum layers, since Al can be relatively difficult to evaporate by means of the known arc discharge.

Boi this evaporator is used as Katode a Glühkatode 13. The common magnet system consists of the Solenoids 14 and 15 and the two evaporator sources are once, as in Fig. 1, the vaporizer crucible 1 for the Evaporation of Ti from the crucible and directly with this as a unit combines an evaporator boat 16 Titanium boride for the evaporation of Al. The Al is fed via a Nachfütterungseinrichtung 17 to the evaporator. When For example, a Ti _x Al _v N, layer is to be produced as wear protection layer for a cutting tool with this evaporator

become. The process is started as in Example I. Thereafter, an anode current of 350A is controlled at the evaporator crucible 1 and at the evaporator boat 16 an anode current of 4OA. The evaporation rates are for Ti at 0.5 g / min and for Al at 0.2 g / min. The ratio of the two evaporation rates to each other can be controlled in this case via the respective anode currents, but also within certain limits via the wire feed rate of the

Al-wire. The nitrogen partial pressure is adjusted to 1 χ 10 " ¹ Pa. If it is technologically advantageous, the mixing ratio can also be varied, for. B. that directly on the substrate

first a pure Ti layer is deposited, then with a gradient a TiN layer and only then again with

Gradient a Ti.AlyN ^ layer. In both embodiments, the variety of possible applications of the evaporator is clearly visible, with the advantage

that only a relatively small technical-economical and spatial effort is required.

In each of the two examples, two vaporizer crucibles or boats were used. It is obvious, however, that too

three or four crucibles are possible, but here is the question of whether the practical need exists that in one

Process cycle so much materials must be evaporated.

Claims (3)

1. arc discharge evaporator with a plurality of evaporator crucibles and a cathode, in particular for the production of mixed and / or multilayers, characterized in that the evaporator crucibles (1,2,16) are insulated from each other, each having a separate power supply and together within the effective range of a common magnet system are arranged for arc steering. 2. arc discharge evaporator according to claim 1, characterized in that one or more evaporator crucibles (1,2,16) isolated Nachfütterungseinrichtungen (17) are assigned. 3. arc discharge evaporator according to claim 1, characterized in that between the evaporator crucibles (1,2,16) steam apertures (9) are present.