DEVICE AND METHOD TO CONTROL THE UNIFORMITY OF A GAS FLOW IN A CVD OR AN ALD REACTOR OR OF A LAYER GROWN THEREIN
A measuring device is provided for determining the position of a susceptor in a reactor housing. The measuring device includes a central element, which can be fastened on the susceptor at a predefined location, and a plurality of sensing arms, which protrude from the central element beyond an outer periphery of the susceptor. The sensing arms respectively include a sensing section that can be brought in touching contact with a contact zone. The contact zone is formed by an inner periphery of the reactor housing or a component arranged in the reactor housing. Using the measuring device, the position of a susceptor of a CVD reactor is determined relative to the reactor housing or a component arranged in the reactor housing.
1 . A measuring device for determining a position of a susceptor ( 3 ) in a reactor housing ( 1 ), the measuring device comprising:
a central element ( 26 ), which is fastened on the susceptor ( 3 ) at a predefined location; and
a plurality of sensing arms ( 29 ), which protrude from the central element ( 26 ) beyond an outer periphery ( 4 ) of the susceptor ( 3 ), wherein said sensing arms respectively include a sensing section ( 30 ) that is brought in touching contact with a contact zone.
2 . The measuring device of claim 1 , wherein the contact zone is formed by an inner periphery ( 2 ) of the reactor housing ( 1 ) or a component ( 21 ) arranged in the reactor housing ( 1 ).
3 . The measuring device of claim 1 , wherein the central element ( 26 ) includes centering means ( 27 , 28 ) which fasten the central element ( 26 ) on the susceptor ( 3 ), and wherein the predefined location is a center of the susceptor ( 3 ).
4 . The measuring device of claim 1 , further comprising communication means configured to wirelessly transmit data through a wall of the reactor housing ( 1 ).
5 . The measuring device of claim 4 , further comprising a battery configured to provide power to the communication means.
6 . The measuring device of claim 1 , further comprising spring elements ( 33 ) which act upon the sensing arms ( 29 ) in a direction extending away from the central element ( 26 ).
7 . The measuring device of claim 1 , further comprising position-measuring elements ( 34 ) which are configured to determine the respective positions of the sensing arms ( 29 ) relative to the central element ( 26 ).
8 . The measuring device of claim 7 , wherein the position-measuring elements ( 34 ) are configured to determine respective distances of the sensing sections ( 30 ) from a center of the measuring device.
9 . The measuring device of claim 2 , wherein each of the sensing sections ( 30 ) includes a sloping flank ( 31 ).
10 . The measuring device of claim 9 , wherein the sloping flanks ( 31 ) of the sensing sections ( 30 ) are arranged in such a way that the sloping flanks ( 31 ) are acted upon by the inner periphery ( 2 ) of the reactor housing ( 1 ) or by the component ( 21 ) arranged in the reactor housing ( 1 ) as the opened reactor housing ( 1 ) is closed and the sensing arms ( 29 ) are displaced toward a center of the susceptor ( 3 ) due to a sliding motion of the inner periphery ( 2 ) of the reactor housing ( 1 ) or the component ( 21 ) along the sloping flanks ( 31 ), wherein the respective distances of the sensing sections ( 30 ) from the center of the susceptor ( 3 ) are determined by means of position-measuring elements ( 34 ).
11 . A method for adjusting a position of a susceptor ( 3 ) relative to a reactor housing ( 1 ) or a component ( 21 ) arranged in the reactor housing ( 1 ), wherein a flow-through area ( 10 ) extends between a gap between an outer periphery ( 4 ) of the susceptor ( 3 ) and an inner periphery ( 2 ) of the reactor housing ( 1 ) or the component ( 21 ), the gap defined by a gap width (S), the method comprising:
fastening a measuring device ( 25 ) on the susceptor ( 3 ) at a predetermined location on the susceptor ( 3 ), the measuring device fastened with a central element ( 26 );
scanning the inner periphery ( 2 ) of the reactor housing ( 1 ) or the component ( 21 ) with sensing sections ( 30 ) formed on sensing arms ( 29 ) that protrude from the central element ( 26 ) beyond the outer periphery ( 4 ) of the susceptor ( 3 );
determining, using the measuring device ( 25 ), the gap width (S); and
adjusting, using adjusting means ( 13 , 14 , 16 ), the position of the susceptor ( 3 ), thereby adjusting the gap width (S).
12 . The method of claim 11 , further comprising:
closing the reactor housing ( 1 ) which causes the inner periphery ( 2 ) of the reactor housing ( 1 ) or the component ( 21 ) arranged in the reactor housing ( 1 ) to act upon sloping flanks ( 31 ) of the sensing sections ( 30 ), which in turn causes the sensing arms ( 29 ) to be displaced towards a center of the susceptor ( 3 ); and
determining, using position-measuring elements ( 34 ), the respective distances between the sensing sections ( 30 ) from the center of the susceptor ( 3 ).
13 . The method of claim 12 , further comprising wirelessly transmitting, via communication means, data regarding the position of the susceptor ( 3 ), as determined by the measuring device ( 25 ).
14 . The method of claim 13 , further comprising providing power to the communication means from a battery.
15 . The method of claim 11 , wherein the position of the susceptor ( 3 ) is adjusted while the reactor housing ( 1 ) is closed and at a reduced total pressure within the reactor housing ( 1 ) and/or at an elevated temperature of the susceptor ( 3 ).
16 . A method for adjusting a position of a susceptor ( 3 ) relative to a reactor housing ( 1 ) or a component ( 21 ) arranged in the reactor housing ( 1 ), wherein a flow-through area ( 10 ) extends between an outer periphery ( 4 ) of the susceptor ( 3 ) and an inner periphery ( 2 ) of the reactor housing ( 1 ) or the component ( 21 ), the method comprising:
adjusting with adjusting means ( 13 , 14 , 16 ) the position of the susceptor ( 3 ) relative to the inner periphery ( 2 ) so as to maximize a lateral uniformity of a gas flow above the susceptor or of a layer grown on one or more substrates lying on the susceptor ( 3 ).
17 . The method of claim 16 , wherein adjusting the position of the susceptor comprises:
adjusting, in a first adjusting step, the position of the susceptor ( 3 ) while the reactor housing ( 1 ) is open; and
adjusting, in one or more second adjusting steps, the position of the susceptor ( 3 ) while the reactor housing ( 1 ) is closed, the first adjusting step and the one or more second adjusting steps maximizing a lateral uniformity of the layer grown on the one or more substrates lying on the susceptor ( 3 ).
18 . The method of claim 17 , further comprising:
varying, in a third adjusting step, a flow of a flushing gas from several flushing gas openings ( 18 ) arranged circumferentially around the susceptor ( 3 ) into the flow-through area ( 10 ) while the reactor housing ( 1 ) is closed, the varying of the flow of the flushing gas further maximizing the lateral uniformity of the layer.
19 . The method of claim 18 , further comprising:
varying, in a fourth adjusting step, a heating power of at least two heating elements ( 19 , 20 ) for heating the susceptor ( 3 ) while the reactor housing ( 1 ) is closed.
20 . The method of claim 19 , wherein one or more of the second, third and fourth adjusting steps are carried out at an elevated temperature and at a reduced pressure in the reactor housing ( 1 ).
21 . The method of claim 20 , further comprising measuring a thickness of the layer or a composition of the layer in situ at different circumferential positions of the susceptor ( 3 ) during one or more of the second, third and fourth adjusting steps.
22 . The method of claim 21 , further comprising repeatedly:
(i) measuring properties of the layer on a peripheral portion of the susceptor ( 3 ) at the different circumferential positions of the susceptor ( 3 ); and
(ii) performing one or more of the second, third and fourth adjusting steps.