DE102013113049A1 - Contact device for connecting a heating element with a contact plate and heating device with such a contact device - Google Patents

Abstract

The invention relates to a device for electrically and mechanically connecting a heating element (10) of a heating device for heating a susceptor of a CVD reactor with a power supply element (36), comprising a head (12), for connection to the heating element (10), a foot (24) for connection to the contact element (36) and a between the head (12) and foot (24) arranged shaft (21). In order to reduce the temperature gradients, it is proposed that the shaft (21) at least in some areas have a smaller cross-sectional area than the head (12). The invention further relates to a heating device for heating a susceptor of a CVD reactor, whose heating element is connected to at least one connector with a power supply element (36).

Description

The invention relates to a device for electrically and mechanically connecting a heating element of a heating device for heating a susceptor of a CVD reactor with a power supply element, comprising a head, for connection to the heating element, a foot for connection to the contact element and an arranged between the head and foot Shaft.

The invention further relates to a heating device for heating a susceptor of a CVD reactor whose heating element is connected to at least one connector with a power supply element.

Connectors for connecting the heating elements of a heating device for heating a susceptor of a CVD reactor, for example, from US 4,292,504 . US 5,759,281 or US 7,645,342 known.

A CVD reactor has a reactor housing, a gas inlet member arranged therein, with which process gases are introduced into a process chamber. The process chamber has a susceptor on which substrates to be coated rest. In order to bring the substrates to coating temperature, the susceptor is heated from below by means of thermal radiation. To generate the heat radiation, a heating device according to the invention is used. The heating device according to the invention has a power supply element, for example in the form of a contact plate, protrude from the connectors. Each connector is connected to at least one heating element. The two ends of each heating element are connected to a connector with two different power supply elements, so that a current can be passed through the heating elements via the power supply elements. These heat up and release their heat in the form of heat radiation to the susceptor. The heating elements heat up to white heat. Extremely temperature resistant heating elements are formed by tungsten wires. The connectors can also be made of tungsten, but also of stainless steel or molybdenum. Since they have a much larger diameter than the heating elements, they have a significantly lower ohmic resistance per unit length than the heating elements. This has the consequence that set at the junctions of the heating elements with the head of the connector very high temperature differences (temperature gradient).

The invention has for its object to provide measures to reduce this temperature gradient.

The object is achieved by the invention specified in the claims, wherein the invention relates both to a particular development of the connector and a heater with such a further developed connector.

First and essentially it is provided that the shaft of the connector at least partially has a smaller cross-sectional area than the head. Preferably, the head of the connector has a cross-sectional area which is larger than the cross-sectional area of a helix of a coiled wire forming the heating element. The wire forming the heating element is preferably a tungsten filament. It can run two filaments next to each other and form a zweigängige helix. The cross-sectional area of the head is preferably more than twice the cross-sectional area of the shaft. The connector preferably has a rectilinear extent. One end of the connector forms the head. The other end of the connector forms a foot. Between the head and foot of the shaft runs. The length of the shaft is preferably greater than the diameter of the shaft. The shaft, the head and the foot may each have a circular cross-sectional area, wherein the cross-sectional area of the foot is greater than the cross-sectional area of the shaft. The cross-sectional area of the foot may correspond to the cross-sectional area of the head. The substantially cylindrical head may merge into the reduced-diameter shank to form a conical section. The shaft can in turn pass to form a conical portion of the foot. The head and the foot may be formed integrally with the shaft. The connector can thus be formed by a milled part. In a variant of the invention it is provided that the head has a channel with a substantially circular cross-section. The opening may be open to the front of the head. The axis of the opening preferably extends transversely to the direction of extension of the shaft. In this channel, a heating element, in particular a coiled filament can be placed. There is provided a fastening means with which the heating element can be fixed in the channel. The fastening element may be a grub screw which is screwed through a threaded bore of the wall of the channel opening. In a further variant, the head can form a contact arm. This contact arm can protrude in the direction transverse to the direction of extension of the axis of the shaft from the head. It can be designed as a plug-in part and stuck with a plug-in in an insertion of the head. The contact arm is connected to the heating element. If the heating element is a coiled filament, the filament can be effectively screwed onto the contact arm. Here are the individual Spiral turns of the filament in threaded trenches of the contact arm. On the filament a sleeve can be attached. The contact arm is then preferably in the sleeve. The inner wall of the sleeve is in touching contact with the filaments of the heating element. In a further variant, which relates to the configuration of the foot of the connector, it is provided that the foot has a conical section. It is a truncated cone section, which preferably follows a cylindrical section. With this frustoconical section, the foot of the connector is inserted in a conical bore of a contact plate. As a result, an optimal contact surface between the connector and the contact plate is given. At the smaller diameter end of the frusto-conical portion, an external thread section connects, on which a fastening nut can be screwed. With the interposition of a washer, the nut is supported on the underside of the contact plate. A securing element is provided in order to prevent the mother from detaching from the external thread during heating and cooling of the heating device. The securing element may be a form-locking element which is inserted through an opening of the male threaded portion. It may have a tongue which can be bent to abut a polygonal surface of the nut or to engage in an axial groove of the outer wall of the nut so as to avoid its rotation.

The special design of the head, namely the channel or the contact arm, and the special design of the foot, namely the conical contact surface, which bears against a conical wall of a contact bore, are independent inventive developments of the prior art.

Embodiments of the invention are explained below with reference to accompanying drawings. Show it:

1 for illustrative purposes only the essential elements of a CVD reactor in a cross-sectional view,

2 a side view of a heater with a total of three heating zones,

3 a top view of the heater,

4 a section along the line IV-IV in 3 .

5 A first embodiment of a connector in the view

6 the in 5 shown connector in a perspective view,

7 in the 5 represented connector in a second side view,

8th a perspective view of a second embodiment of a connector,

9 the section according to the line IX-IX in 8th .

10 the section according to the line XX in 8th .

11 an enlarged section 10 .

12 the bottom view according to arrow XII in 10 .

13 an exploded view of the in the 8th Perspective illustrated embodiment,

14 the perspective view of a third embodiment and

15 the section according to the line XV-XV in 14 ,

The 1 shows the basic structure of a CVD reactor, with a large number required for the operation of a CVD reactor aggregates are not shown for clarity. In a gas-tight housing 1 there is a gas inlet organ 2 , which are supplied with process gases, carrier gases and purge gases with gas supply lines, not shown. These gases pass through gas outlet openings in a process chamber 3 one whose bottom is from a susceptor 5 is formed on the substrates 4 rest, which are coated. These may be silicon substrates or III-V substrates on which semiconductor layers, insulating layers or conductive layers are deposited. The coated graphite susceptor 5 is from below by means of a heater 6 heated.

That above the process chamber 3 arranged gas inlet member 2 can be actively cooled. It thus forms a steep temperature gradient between the heater 6 and gas inlet member 2 out. The heater 6 must provide sufficient heat output to that to the process chamber 3 facing surface of the susceptor 5 to heat to temperatures above 1,000 ° C.

At these temperatures, the introduced into the process chamber react gaseous Process gases, which may be organometallic compounds of elements of III. Or II. Main group and hydrides of IV., V. or VI. Main group.

The 2 to 4 show a typical heater as used in the 6 is shown schematically. The heater 6 consists of three heaters 7 . 8th . 9 , A central heating is provided by a circular heating plate 7 formed by two annular heaters 8th . 9 is surrounded. Each of the three coaxial nested heaters 7 . 8th . 9 can be energized independently of the other heating.

Each of the heaters 7 . 8th . 9 has one or more heating elements 10 which is wound on a spiral line around the center of the entire heating device. There are several on the spiral line one behind the other heating elements 10 provided, each with connectors 11 with contact plates 36 are connected. The contact plates 36 Serve the power supply, allowing through the heating elements 10 a current can flow through it. The heating elements 10 are not shown in detail for the sake of clarity.

The 5 to 7 show a first embodiment of the invention to a heating element 10 with a contact plate 36 connect to.

At the heating element 10 it is a twin filament, which consists of two helically wound tungsten wires. The heating element 10 extends in a parallel plane to the plane of the contact plate 36 , With the connector 11 is the end of the heating element 10 , so the last passages of the filament, with the contact plate 36 connected.

The connector 11 has a head 12 who has a channel 14 has, which has a circular cross-section. The channel axis runs transversely to the longitudinal axis of the connector 11 , In the channel are turns of the filament 10 , The channel 14 is to the face of the head 12 open. By means of a grub screw 15 in a tapped hole of the wall of the canal 14 is screwed in, the heating element can 10 in the canal 14 be fixed.

The head 12 has a substantially circular cross-section. The channel 14 is located in a the end of the connector 11 associated cylindrical section. This, the head forming cylindrical portion goes to form a truncated cone portion 22 in a circular cylindrical shaft 21 above. The axis of the shaft 21 defines the longitudinal axis of the connector 21 , The diameter of the shaft 21 is less than the diameter of the head 12 , The cross-sectional area of the shaft 21 is less than 50 percent of the cross-sectional area of the head 12 ,

To the shaft 21 closes another truncated cone section 23 which is in an enlarged diameter section 25 passes. It is a cylinder section 25 whose diameter is the diameter of the head 12 equivalent. Also the cylinder section 25 has a circular floor plan.

The cylinder section 25 belongs to a foot 24 of the connector 11 with which the connector 11 with the contact plate 36 connected is. To maximize contact between connector 11 and contact plate 36 to ensure owns the foot 24 a frusto-conical contact portion 26 that in a conical bore 37 the contact plate 36 plugged.

That the head 12 opposite end of the connector 11 is from a male threaded section 27 trained on which a mother 25 is screwed on. With the interposition of a washer 34 into which is the conical section 26 can extend into it, the mother is supported 25 at the bottom of the contact plate 36 on to the truncated cone section 26 to apply a tensile stress.

The connector 11 is essentially a rotationally symmetrical body whose head 12 , Shank 11 and foot 24 form a common extension axis. The connector 11 can be designed as a milled part. It can be used a cylindrical blank in which the shaft 11 and the truncated cone sections 22 . 23 . 26 and the male threaded portion 27 be produced by a machining.

During heating and cooling, a thermal movement occurs. To prevent this while the mother 35 from the external thread 27 triggers is a security element 31 intended. The fuse element 31 is a small plate with a tongue 32 , The tongue forms the T-bridge of a T-shaped body. The two T-thighs 33 form retaining bars. The tongue 32 gets into a narrow transverse opening 29 through the male threaded portion 27 through put. The end of the tongue 32 It is then bent up towards the nut to attach itself to one of the polygonal surfaces of the nut 35 to apply.

The slot 29 is by means of a slot section 30 to the front 28 of the external thread section 27 open. The slot for inserting the tongue 32 of the fuse element 31 thus has a T-shaped cross-section.

That in the 8th to 13 illustrated embodiment differs from the first embodiment substantially only by the shape of the mother 35 and the electrical contacting of the filament 10 at the head 12 , The mother 35 is designed here as a knurled nut. It has grooves running in the axial direction, which alternate with webs extending in the axial direction. Into the grooves can the high bent tongue 32 of the fuse element 31 be inserted. The head 12 of the connector 11 has a hole 17 in which a male end of a contact arm 16 is plugged in. The contact arm 16 thus extends transversely to the extension direction of the connector 11 or the shaft 21 of the connector 11 , On the free end of the cross from the head 12 protruding contact arm 16 there is an internal thread 18 , The internal thread 18 carrying section of the contact arm 16 is slightly conical. The head 12 forms a step 19 from, which is formed by a recess. The cross to the stage 19 running wall carries the opening of the hole 17 from which the threaded section 18 of the contact arm 16 protrudes.

The contact arm 16 is with his thread 18 in the helical filament 10 screwed in so that the wires insert into the trenches of the threads

Both embodiments serve not only to mechanically hold the filament, but also the filament 10 to supply electricity.

As the diameter of the filament 10 is considerably smaller than the diameter of the connector 11 , owns the filament 10 a much greater resistance per unit length than the filament 10 , which has the consequence that over the length of the connector 11 significantly less tension drops than about the same length of filament 10 , As a result, the filament heats up 10 considerably stronger than the connector 11 , The filament is heated to temperatures well above 1000 ° C. With the reduced diameter portion of the shaft 21 is formed, the resistance per unit length in the region of the connector 11 reduced. This has the consequence that the connector 11 heats appreciably in the area of the shaft. As a result, the temperature gradient in the head 12 is lower than he is with a larger diameter shaft 21 would.

In the in the 14 and 15 illustrated embodiment is on the contact arm 16 a sleeve 20 attached. The sleeve extends over the entire contact arm 16 and is in touching contact with the opening 17 training edge of the stage 19 , The sleeve 20 extends in a transverse direction to the extension direction of the connector 11 , The filaments 10 lie on the inner wall of the sleeve 20 and thereby become mechanically in the threads 18 held.

The contact arm 16 preferably also consists of tungsten. The insertion end of the contact arm 16 can with a screw, not shown, or a split pin in the opening 17 be fixed. The insertion can also be slightly conical, so that a conical surface on the inner wall with a then conical opening 17 is applied.

The above explanations serve to explain the inventions as a whole covered by the application, which independently further develop the state of the art, at least by the following combinations of features, namely:
A device characterized in that the shaft 21 at least partially has a smaller cross-sectional area than the head 12 ;
A device characterized in that the cross-sectional area of the shaft 21 less than 50 percent of the cross-sectional area of the head 12 is;
A device which is characterized in that the head, in particular having a circular cross-section 12 forming a conical section 22 in the particular having a circular cross-section shaft 21 passes, the length of the shaft 21 is greater than its diameter;
A device characterized in that the cross-sectional area of the foot 24 is greater than the cross-sectional area of the shaft and in particular approximately the cross-sectional area of the head 12 corresponds;
A device characterized in that the axial length of the head 12 about the diameter of the head 12 corresponds;
A device characterized in that the heating element 10 is formed by at least one coiled wire;
A device characterized in that the head 12 a particular transverse to the direction of extension of the shaft 21 extending channel 14 has for receiving the heating element 10 which is in the canal 14 in particular by means of a screw 15 is secured;
A device characterized in that the head 12 a contact arm 16 comprising the heating element 10 carries, wherein the heating element 10 is formed in particular by two coiled wires running side by side, in threaded trenches 18 of the contact arm 15 einliegen and is provided in particular that in the threaded trenches 18 enclosed Wendelgangabschnitte in a sleeve 20 stuck;
A device characterized in that the foot 24 a truncated cone section 26 which is in a conical bore 37 one the power supply element 36 forming contact plate inserted, wherein it is provided in particular that to the smaller diameter end portion of the truncated cone portion 26 an external thread 27 connects, on which a mother 35 can be screwed, in particular, it is provided that the mother 35 by means of a securing element 31 is rotationally secured;
A device characterized in that the head 12 contact means 14 . 16 forms, with which a formed by a wire helix heating element 10 with the head 12 mechanically and electrically connectable;
A device characterized in that the foot 24 a truncated cone section 26 having, with its stump end in an externally threaded portion 27 passes.

All disclosed features are essential to the invention (individually, but also in combination with one another). The disclosure of the associated / attached priority documents (copy of the prior application) is hereby also incorporated in full in the disclosure of the application, also for the purpose of including features of these documents in claims of the present application. The subclaims characterize with their features independent inventive developments of the prior art, in particular to make on the basis of these claims divisional applications.

LIST OF REFERENCE NUMBERS

1

CVD reactor

2

gas inlet

3

process chamber

4

substratum

5

susceptor

6

heater

7

heater

8th

heater

9

heater

10

filament

11

connector

12

head

13

face

14

channel

15

screw

16

contact

17

drilling

18

thread

19

recess

20

shell

21

shaft

22

Truncated cone section

23

Truncated cone section

24

foot

25

cylinder section

26

Truncated cone section

27

Externally threaded section

28

face

29

slot

30

slot portion

31

fuse element

32

tongue

33

holding web

34

washer

35

mother

36

contact plate

37

Contact hole

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 4292504 [0003]
• US 5759281 [0003]
• US 7645342 [0003]

Claims (13)

Device for electrically and mechanically connecting a heating element ( 10 ) a heating device ( 6 ) for heating a susceptor ( 5 ) of a CVD reactor ( 1 ) with a power supply element ( 36 ), having a head ( 12 ), for connecting to the heating element ( 10 ), one foot ( 24 ) for connection to the contact element ( 36 ) and one between head ( 12 ) and foot ( 24 ) arranged shaft ( 21 ), characterized in that the shaft ( 21 ) at least partially has a smaller cross-sectional area than the head ( 12 ). Device according to claim 1, characterized in that the cross-sectional area of the shank ( 21 ) less than 50 percent of the cross-sectional area of the head ( 12 ) is. Device according to one of the preceding claims, characterized in that the in particular a circular cross-section head ( 12 ) forming a conical section ( 22 ) in which in particular a circular cross section having shank ( 21 ), whereby the length of the shaft ( 21 ) is greater than its diameter. Device according to one of the preceding claims, characterized in that the cross-sectional area of the foot ( 24 ) is greater than the cross-sectional area of the shaft and in particular approximately the cross-sectional area of the head ( 12 ) corresponds. Device according to one of the preceding claims, characterized in that the axial length of the head ( 12 ) about the diameter of the head ( 12 ) corresponds. Device according to one of the preceding claims, characterized in that the heating element ( 10 ) is formed by at least one coiled wire. Device according to one of the preceding claims, characterized in that the head ( 12 ) one in particular transversely to the direction of extension of the shaft ( 21 ) extending channel ( 14 ) has for receiving the heating element ( 10 ), which in the channel ( 14 ) in particular by means of a screw ( 15 ) is secured. Device according to one of the preceding claims, characterized in that the head ( 12 ) a contact arm ( 16 ) having the heating element ( 10 ), wherein the heating element ( 10 ) is formed, in particular, by two coiled wires running side by side, which are arranged in threaded trenches ( 18 ) of the contact arm ( 15 ) and in particular it is provided that the in the thread trenches ( 18 ) enclosed Wendelgangabschnitte in a sleeve ( 20 ). Device according to one or the preceding claims, characterized in that the foot ( 24 ) a truncated cone section ( 26 ), which in a conical bore ( 37 ) one of the power supply element ( 36 ) forming contact plate, wherein it is provided in particular that at the smaller diameter end portion of the truncated cone portion ( 26 ) an external thread ( 27 ), to which a mother ( 35 ) is screwed, in particular, it is provided that the mother ( 35 ) by means of a securing element ( 31 ) is rotationally secured. Device for electrically and mechanically connecting a heating element ( 10 ) a heating device ( 6 ) for heating a susceptor ( 5 ) of a CVD reactor ( 1 ) with a power supply element ( 36 ), having a head ( 12 ), for connecting to the heating element ( 10 ), one foot ( 24 ) for connection to the contact element ( 36 ) and one between head ( 12 ) and foot ( 24 ) arranged shaft ( 21 ), characterized in that the head ( 12 ) Contact agent ( 14 . 16 ) forms, with which a heating element formed by a wire helix ( 10 ) with the head ( 12 ) is mechanically and electrically connectable. Device for electrically and mechanically connecting a heating element ( 10 ) a heating device ( 6 ) for heating a susceptor ( 5 ) of a CVD reactor ( 1 ) with a power supply element ( 36 ), having a head ( 12 ), for connecting to the heating element ( 10 ), one foot ( 24 ) for connection to the contact element ( 36 ) and one between head ( 12 ) and foot ( 24 ) arranged shaft ( 21 ), characterized in that the foot ( 24 ) a truncated cone section ( 26 ), which with its stump end in an externally threaded portion ( 27 ) passes over. Heating device for heating a susceptor ( 5 ) of a CVD reactor ( 1 ) with a power supply element ( 36 ) and at least one heating element ( 10 ), characterized in that the heating element ( 10 ) with a device according to one or more of the preceding claims with the power supply element ( 36 ) connected is. Device characterized by one or more of the characterizing features of one of the preceding claims.

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