EPITAXIAL REACTOR WITH SUSCEPTOR CONTROLLED POSITIONING

• US 20090107404A1
• Filed: 07/30/2004
• Published: 04/30/2009
• Est. Priority Date: 07/30/2004
• Status: Abandoned Application

• Current Assignee: LPE S.p.A. (ASM International NV)
• Original Assignee: Katten Muchin Rosenman LLP
• Inventors: Ogliari, Vincenzo, Preti, Franco, Tarenzi, Giuseppe
• Application Number:
  US11/658,825
• Publication Number:
  US 20090107404A1
• Time in Patent Office: Days
• US Class Current: 118/729
• CPC Class Codes: C23C 16/4584 the substrate being rotated
• CPC Class Codes: C30B 25/16 Controlling or regulating controlling or regulating in general G05

Abstract

The invention relates to a system for controlling the positioning of a susceptor (2) rotating in the reaction chamber (3) of an epitaxial reactor. The control is carried out on the basis of the different path of a laser beam transmitted by a source (15) when it is reflected by a pin (8) arranged on the susceptor (2).

Claims

1. A reactor for chemical vapour deposition comprising:

a reaction chamber, a susceptor which can be moved in the chamber, a transmitting means to transmit electromagnetic radiation towards the susceptor, and a detecting means to detect the radiation, at least one projecting reference element seated on the susceptor, capable of reflecting the radiation towards said detecting means for detecting it.

2. A reactor according to claim 1, in which the means for transmitting the electromagnetic radiation and those for detecting it are arranged outside the reaction chamber (3).

3. A reactor according to claim 2, in which the electromagnetic radiation is of the luminous type and the walls of the reaction chamber are transparent to this radiation.

4. A reactor according to claim 3, in which the luminous radiation comprises a laser beam.

5. A reactor according to claim 1, in which said reference element comprises a pin projecting relative to the surface of the susceptor.

6. A reactor according to claim 5, in which the pin comprises a flat head.

7. A reactor according to claim 6, in which the pin comprises a base for seating it on the susceptor.

8. A reactor according to claim 7 in which the base of the pin is seated in a hollow formed on the surface of the susceptor.

9. A reactor according to claim 1, in which the reference element is made of the same material as the susceptor.

10. A reactor according to claim 9, in which said material is graphite-based.

11. A reactor according to claim 1, in which the susceptor rotates relative to an axis (X) and its rotational movement is brought about by electronically controlled initialisable operating means.

12. A reactor according to claim 1, in which the means for transmitting electromagnetic radiation towards the susceptor and those for detecting the radiation reflected by it are incorporated in a module which can be moved between an operating position directed towards the susceptor and a non-operating position in which said module is moved away relative to the reaction chamber.

13. A reactor according to claim 1, comprising a window in the area of the reaction chamber through which the electromagnetic radiation passes, capable of avoiding scattering of the radiation.

14. A susceptor for a reactor according to claim 1, characterised in that it comprises a hollow on its face intended for the support of substrates, to provide a seating for a base of a projecting element capable of reflecting said electromagnetic radiation.

15. A susceptor for a reactor according to claim 1, characterised in that it comprises a protuberance on its face intended for supporting substrates, capable of reflecting electromagnetic radiation.

16. A method for controlling the position of a susceptor (2) of a reactor for chemical vapour deposition, the method comprising the steps of:

arranging an element projecting from the surface of the susceptor, capable of reflecting electromagnetic radiation;

projecting a beam of electromagnetic radiation onto the susceptor in motion;

detecting the difference of the path of the beam when it is reflected by the projecting element;

inputting the position of the susceptor following the detection of the different path of the beam;

causing movement of the susceptor on the basis of the position input.

17. A method according to claim 16, also comprising the following steps for inputting the position of the susceptor:

moving the susceptor for a predetermined time, acquiring the mean of the values of the distance travelled by the incident beam;

halting the susceptor in a predetermined space when this distance varies as a result of the projecting element passing under the beam;

moving the susceptor backwards, returning the projecting element into the position under the beam;

initialising the susceptor using this position as reference.