Microwave plasma reactors
First Claim
1. A microwave plasma assisted reactor comprising:
- (a) a first microwave chamber having a reference plane at a reference axial location Zo and extending in an axial direction z>
Zo, wherein the first microwave chamber comprises;
(i) a first cylindrical waveguide section positioned adjacent the reference axial location Zo, extending in the axial direction z>
Zo away from the reference axial location Zo, and having a radius of R1a;
(ii) a second cylindrical waveguide section positioned adjacent the first cylindrical waveguide section, extending in the axial direction z>
Zo away from the first cylindrical waveguide section, and having a radius of R1b such that R1b/R1a is greater than 1; and
iii) an electromagnetic wave source;
(b) a plasma chamber having an outer wall defining a cylindrical cross section with radius of R2, the plasma chamber extending into the first cylindrical waveguide section of the first microwave chamber such that at least a portion of the plasma chamber is located at z>
Zo;
(c) a conductive stage defining a cylindrical cross section with radius of R3 and having a reference surface extending into the plasma chamber and defining a second microwave chamber in the plasma chamber (i) at z<
Z.sub.0 and (ii) between the plasma chamber outer wall and the conductive stage; and
(d) a conducting short adjustably disposed in the second microwave chamber below Zo and in electrical contact with and movable with respect to the plasma chamber outer wall and the conductive stage, the axial distance between the conducting short and Zo being L2, and the axial distance between the conducting short and the reference surface of the conductive stage being L1;
wherein;
R3/R2 is 0.5 or less; and
geometric scales of the reactor are configured such that, during operation of the reactor, electromagnetic fields are produced in the vicinity of Zo and in the plasma chamber, the electromagnetic fields comprising one or more of a TM01 mode, a TEM001 mode, and evanescent modes.
2 Assignments
0 Petitions
Accused Products
Abstract
Microwave plasma assisted reactors, for example chemical vapor deposition (MPCVD) reactors, are disclosed. The disclosed reactors operate at high pressures (>180-320 Torr) and high power densities (>150 W/cm3), and thereby enable high deposition rate CVD processes that rapidly deposit materials. In particular, reactor design examples are described that, when operating in the 180-320 Torr pressure regime, rapidly CVD synthesize high quality polycrystalline (PCD) and single crystal diamond (SCD). The improved reactors include a radial contraction in the vicinity of the plasma chamber (and optionally a combined expansion in the vicinity of the electromagnetic wave source, followed by the contraction) in the main microwave chamber as electromagnetic energy propagates from an electromagnetic wave source to a plasma/deposition chamber.
-
Citations
11 Claims
-
1. A microwave plasma assisted reactor comprising:
-
(a) a first microwave chamber having a reference plane at a reference axial location Zo and extending in an axial direction z>
Zo, wherein the first microwave chamber comprises;(i) a first cylindrical waveguide section positioned adjacent the reference axial location Zo, extending in the axial direction z>
Zo away from the reference axial location Zo, and having a radius of R1a;
(ii) a second cylindrical waveguide section positioned adjacent the first cylindrical waveguide section, extending in the axial direction z>
Zo away from the first cylindrical waveguide section, and having a radius of R1b such that R1b/R1a is greater than 1; andiii) an electromagnetic wave source; (b) a plasma chamber having an outer wall defining a cylindrical cross section with radius of R2, the plasma chamber extending into the first cylindrical waveguide section of the first microwave chamber such that at least a portion of the plasma chamber is located at z>
Zo;(c) a conductive stage defining a cylindrical cross section with radius of R3 and having a reference surface extending into the plasma chamber and defining a second microwave chamber in the plasma chamber (i) at z<
Z.sub.0 and (ii) between the plasma chamber outer wall and the conductive stage; and(d) a conducting short adjustably disposed in the second microwave chamber below Zo and in electrical contact with and movable with respect to the plasma chamber outer wall and the conductive stage, the axial distance between the conducting short and Zo being L2, and the axial distance between the conducting short and the reference surface of the conductive stage being L1; wherein; R3/R2 is 0.5 or less; and geometric scales of the reactor are configured such that, during operation of the reactor, electromagnetic fields are produced in the vicinity of Zo and in the plasma chamber, the electromagnetic fields comprising one or more of a TM01 mode, a TEM001 mode, and evanescent modes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
Specification