DE1521421A1 - Process for the vapor deposition of thin layers and apparatus for carrying out this process - Google Patents

Description

DlpL-Ing. H. ZOEPKE _to pbb 31,376

- ßidlerstraß W 1 Ö Z I 4 Z 1

Η. V. PHILIPS 'GLOEILAMPENFABRIEKEN, EINDHOVEN / HOLLAND

"Process sum evaporation of thin layers and apparatus for carrying out this process" ·

The invention relates to evaporation sources for the evaporation of thin soles on a substrate as a method for Applying thin splints

Be has known that there is foam on the surface

to of an evaporating metal or an evaporating alloy

CO partially affects) veil Sohauateilohen from the evaporating surface

^ can be thrown out and built into the deposited Sohioht. "Λ. The Sohaumeohollen on the surface have a different Euiesionsver-

ro as the pure metal surface, i.e. not covered with foam, cn

and these kaiin temperature gradients bring about on this surface, whence the condensation of the steam fluctuates, if the relationship

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the activity coefficient of the constituents of an alloy Function of the temporature is. This difficulty leaves me with one Overcoming the curvature of the evaporating surface that causes the Foam is held all around the hand of the crucible "

Bio duroh vapor deposition layers produced can result radial Aeηderungeη the incident Dampfetrahlea and depending on the angle at which the material to the backing gelangtι in the thickness, composition and άβη physical properties vary · Therefore, should a suitable Verdampfungequelle only flume radial fluctuations in the vapor stream, and slight fluctuations in the composition, while it must still be able to deliver a large amount of water in the unit of time, so that it can be used at a greater distance from the base »whereby changes in the angle of incidence are limited to a minimum ·

With a suitable source of evaporation, the metal to be evaporated is arranged to form a convex meniscus such that the foam is retained in a specific zone on the molten surface of the material. In this way foam-free material can evaporate from the remaining part of the surface A single source of evaporation is only satisfactory for a limited period of time because the meniscus decreases until the Foam is no longer restricted to the required zone · Another Nearly part of such a source of evaporation is »that sioh when it is used

Vapor deposition of a logging is used «the composition of the le- O gation during the evaporation process changes if the activity coefficient

OO cients of the components of the alloy are different, cn

^ The purpose of the invention is to provide a source of evaporation

_4 ben that take advantage of the evaporation source described above tv)

cn has »and can be used either continuously or intermittently for a long time without affecting the composition of the vaporized * SAD ORIGINAL

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.152H21

Material changes inappropriately, improving the process

according to patent (Pat.Ag. H 26 428 VH) / 48b).

According to the invention is a method for vaporization

of material from the Fluesigkeitephaae and sum down theees Material on a base characterized in that the to be evaporated Material is filled up during evaporation, eo that the foam on the surface of the material not covered by the crucible kept moist in the zone surrounding the vaporization surface and furthermore the desired composition of the material to be evaporated is maintained.

According to the invention, a device includes M evaporation of material from the Fluesigkeitsphaae and for depositing this material on a base, a floating crucible which has a channel that pre-binds the interior of the sohvrimmenden crucible with a container, the molten material with a for the evaporation may contain the desired composition. The device enables good control of the composition of the vapor.

The invention is explained in more detail below with reference to the accompanying drawing, in which

Fig. 1 shows a child through a first embodiment an evaporation source and ^

2 shows a section through a second embodiment represents an evaporation source.

The evaporation source naoh Fig. 1 consists of a cylindrical Inner crucible 1, which contains the material to be evaporated 2 and sohwimrat in a container 3, which is in a cylindrical outer crucible 4 is arranged. The material in container 3 has the same feed

O aamraensetzung as the material 2 in Innentiogel 1. A channel 5 "which""* extends from the Innenoberfläohe 6 to 7 Auseenoberfläche dea Bodonu of the inner tiogels ^ _n 1, connects dos material 2 with the container 3" bo that the to- evaporating soulsene material duroh the canal hinduoh

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152U21

can flow into the Innon crucible 1. The inner crucible 1 is through weights 8 attached to the upper edge 9.

In the embodiment of the Verdarapfungequelle naoh Fig. 1 UUOS the HChe height _? of the meniscus of the material to be evaporated above the edge 9 must be greater than a certain critical value in order to achieve that the foam is retained in a zone at the edge of the meniscus in which the radius of curvature of the surface of the material 2 is smallest. This critical value can be determined experimentally and it was found with 50/50 Niokel-iron alloys that the Sohaura was caught and held when ι

where R. is the inner radius of the inner crucible Q 1 in on *

The dimensions of the source must be based on the approximate simultaneous relationships for the pressure at the base of the channel 5 on the Point at which this opens into the container 3, to be determined. It is therefore true

₁ £ - Tg (h ₂ + H ₁ + H ₂ ) + 1 ^ - Mg (W Γ ¹ (1)

wobeil

P is the density of the material to be evaporated)

g is the constant of gravity)

jf is the surface tension of the eu evaporating material

is (believed to be the material of the

Inner and outer pan not wetted)} CO

O M the entire Maaee of the inner crucible 1 (einohliesslioh OO the accustomed Θ) and its content is ι

° h ₁ the height of the material inside and outside of the tank

_ * is, from the bottom surface 7 of the inner crucible 1 gel » measure cn}

hg the height of the meniscua above the edge 9 of the crucible 1 istj

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152U21

IL is the depth of the inner level 1 between the hand 9

and the surface f- istj H "the distance between the inner surface and the

Auusenoberfleiche 7 of the crucible 1 is} r. half of the middle Abatanu.ee zn laugh the

Inner pan 1 and the outer pan & el 4) r_ the radius of curvature of the surface to be evaporated Material perpendicular to the axis of symmetry through the center of the Innontieüolsj and

H is the outer radius of the inner crucible 1. %

The inner crucible 1 and the Auseentiegel 4 are made of a material that does not react with the material to be evaporated. If the 50 / $ Q Hiokel-Eisen-Leijiorunij is used, the crucible material must be e.g. aluminum oxide or zirconium oxide. The distance (mean value 2r.) Between the inner crucible 1 and the outer crucible 4 must be as small as possible in order to limit evaporation from the container.

In operation, a pellet of the to be evaporated

Material arranged in the crucible 1, which is on the material 3 in the container rests. The ause crucible 4 is then heated to a first temperature, in which the material to be evaporated and the material in the container are in the molten state · This temperature is maintained) until Most of the enclosed oasis have been driven out. The temperature The outer crucible 4 is then raised and the heat radiates from the upper one

CO edge of the outer crucible 4 on the surface of the to be evaporated O

* ° Material in crucible 1, causing local heating and evaporation Oo

_o from the surface of the material in crucible 1. By doing

~ »Masee ^ in which the material evaporates from the inner crucible 1, becomes new Material is fed through the channel 5 from the container 3 so that the

The shape of the meniscus on the material in the inner crucible is retained «

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The heating can take place in any suitable manner. For example, if the outer pan is made of a conductive Material ordered, this material through Elektrononbeachuoo or High frequency heating. It is also possible to use the crucible, if made of an insulating material, radiation or line from another body (e.g. the jacket in Fig. 2) to be heated, or to be pre-steamed by dissipating high-frequency energy do.a Adding heat to the material

In some cases where the activity coefficient the constituents of an alloy to be evaporated are different from one another Bind, it may be necessary that the composition of the material Separate the inner crucible from that of the material in container 3 is, in which case the length L and the radius K dots canal are such Must have values that the flow velocity through the channel is greater than the diffusion of material in the opposite direction In order to accomplish this bodining: the following equation is satisfied will be

' ξ (2)

wobeit

ν is the rate of evaporation from the inner crucible

1 is in cm ³ / β and
D is the coefficient of diffusion for the fastest

moving bed part of the liquid is *

In the embodiment shown in FIG. 2, (O

"Corresponding part" with the same reference numerals as in Fig. 1 denote (D

The inner crucible 1 is in the container 3 with the help of the weights 3, the σ
- ^ attached to the surface 7 of the crucible 1 by means of a stem 10

"" * are kept at the required level · The outer pan 4 is from

may be a dumbbell 11 surrounded heated duroh the electron bombardment or other means not shown · DQV rtand of Innentie {, ice can 1

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extend further, this is indicated by dashed lines in FIG. 2 is ι to evaporate the heat radiation on the surface Reinforce material in crucible 1. The maximum distance 2 r, between doia stem 1Ü and the Auosentiegel 4 and dom jacket 11 is through the the following QleicLn.'ij botstianti

■ f > PjH, + Mß & * Γ ¹ (3)

.t-ο be it

Jf 'the überfltlchena ^ annunt * eng au evaporated material

lot, (assuming) that this is the material f of the inner or outer crucible not wetted); P the density of the material to be evaporated iatj g the gravitational constant ietj R is the outer half berry of the inner pot; H- the depth of the liquid in the container 3 under the

Surface 7 eats, and M is the total mass of the inner crucible oil 1 (including

the weight and its content is Equations (1) and (2) obviously also apply to the embodiment of FIG. 2, while the mode of operation is almost the same.

The jacket 11 can consist of an electrically conductive

Order material bo that it can be heated by electron beechusa can, whereby the heat is conducted to the outside gate 4

909850/1125 bath

Claims (1)

PHB 31.376 152U21 PATEHfAlTS PRUECHEi 1. Procedure for the preparation of material from the liquid hoituphaue and for unloading diococ materials on an underground, in this way, the fact that the material is to be preceded during the The vaporization process is refilled so that the foam on the surface of the material in which the evaporation is not covered by the crucible curses surrounding "one held and the {respective . sarameneetsun & the zti evaporating material is retained 2 «Method according to claim 1, characterized in that the material that serves as a refill for the vaporized material, a Zuoamnennetzuni; that is different from that of the evaporated KaterialB distinguishes 3 Device for vaporizing material from the flow keitsphaee and for the deposition of the material on a base alt the help of a method according to the preceding Anei'rUchen, characterized by the fact that the device contains a floating Tiotfel, which has a channel, the inside ueo floating crucible with a 'Connects the container, the material having a geeolunolzenes Zuaaamensetsutig "as it should have the evaporating material containing x 4 * apparatus according to claim 3, characterized in that A & ao the floating crucible is weighed down, go that it is on a previous l »- the level in the molten material in the container floats » > · Device according to claim 3 or 4, daduroh recognized net, because the container is surrounded by an electrically conductive jacket will" Patent (PatdLg · H 26 428 TIb / 48b) 909850/1125 ^ba d original