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 Z0, the first microwave chamber comprising an electromagnetic wave source and extending in an axial direction z>
Z0;
(b) a plasma chamber having an outer wall, the plasma chamber extending into the first microwave chamber such that at least a portion of the plasma chamber is located at z>
Z0 and at least a portion of the plasma chamber is located at z<
Z0;
(c) a conductive stage for supporting a substrate holder and having a reference surface extending into the plasma chamber and defining a second microwave chamber in the plasma chamber (i) at z<
Z0 and (ii) between the plasma chamber outer wall and the conductive stage;
(d) a conducting short adjustably disposed in the second microwave chamber below Z0 and in electrical contact with the plasma chamber outer wall and the conductive stage, the axial distance between the conducting short and Z0 being L2, and the axial distance between the conducting short and the reference surface of the conductive stage being L1;
wherein L2 and L1 are capable of adjustment in the reactor by moving the conducting short, such that different microwave modes are produced in the first microwave chamber and in the second microwave chamber during operation of the reactor.
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Accused Products
Abstract
New and improved microwave plasma assisted reactors, for example chemical vapor deposition (MPCVD) reactors, are disclosed. The disclosed microwave plasma assisted reactors operate at pressures ranging from about 10 Torr to about 760 Torr. The disclosed microwave plasma assisted reactors include a movable lower sliding short and/or a reduced diameter conductive stage in a coaxial cavity of a plasma chamber. For a particular application, the lower sliding short position and/or the conductive stage diameter can be variably selected such that, relative to conventional reactors, the reactors can be tuned to operate over larger substrate areas, operate at higher pressures, and discharge absorbed power densities with increased diamond synthesis rates (carats per hour) and increased deposition uniformity.
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Citations
23 Claims
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1. A microwave plasma assisted reactor comprising:
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(a) a first microwave chamber having a reference plane at a reference axial location Z0, the first microwave chamber comprising an electromagnetic wave source and extending in an axial direction z>
Z0;(b) a plasma chamber having an outer wall, the plasma chamber extending into the first microwave chamber such that at least a portion of the plasma chamber is located at z>
Z0 and at least a portion of the plasma chamber is located at z<
Z0;(c) a conductive stage for supporting a substrate holder and having a reference surface extending into the plasma chamber and defining a second microwave chamber in the plasma chamber (i) at z<
Z0 and (ii) between the plasma chamber outer wall and the conductive stage;(d) a conducting short adjustably disposed in the second microwave chamber below Z0 and in electrical contact with the plasma chamber outer wall and the conductive stage, the axial distance between the conducting short and Z0 being L2, and the axial distance between the conducting short and the reference surface of the conductive stage being L1; wherein L2 and L1 are capable of adjustment in the reactor by moving the conducting short, such that different microwave modes are produced in the first microwave chamber and in the second microwave chamber during operation of the reactor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A microwave plasma assisted reactor comprising:
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(a) a cylindrical chamber defining an interior cylindrical microwave chamber of radius R1 and having (i) a central axis, (ii) a lower boundary at a reference axial location Z0, and (iii) a upper boundary at an axial location Zu>
Z0; and(b) a base defining an interior base cavity of radius R2 and having (i) an upper boundary adjacent the cylindrical chamber at Z0 and (ii) a lower portion extending axially downwardly in a direction z<
Z0;(c) an upper conducting short in electrical contact with the cylindrical chamber and disposed in an upper portion of the cylindrical chamber at an axial distance Ls above Z0, the upper conducting short having a central opening and defining the upper boundary of the cylindrical chamber; (d) an excitation probe extending through the central opening of the upper conducting short and into the upper portion of the cylindrical microwave chamber by an axial distance Lp relative to the upper boundary of the cylindrical chamber; (e) a coaxial stage for supporting a substrate holder and having a radius R3 and an upper surface extending at least into the base cavity and optionally into a bottom portion of the cylindrical microwave chamber, the coaxial stage defining a coaxial microwave chamber between R3 and R2 in the base cavity, wherein the coaxial stage is conductive; (f) a lower conducting short adjustably disposed in the coaxial microwave chamber below Z0 and in electrical contact with the base and the coaxial stage, the axial distance between the lower conducting short and Z0 being L2 and the axial distance between the lower conducting short and the upper surface of the coaxial stage being L1; (g) a quartz bell jar mounted on the base and defining a plasma chamber in the bottom portion of the cylindrical microwave chamber and the coaxial microwave chamber; (h) a feed gas inlet in fluid connection with the plasma chamber; and
,(i) an effluent gas outlet in fluid connection with the plasma chamber;
whereinL2 and L1 are capable of adjustment in the reactor by moving the lower conducting short. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification