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US 11,001,926 B2Granted
Apparatus and method for the reduction of impurities in films
AssigneeGallium Enterprises Pty Ltd
InventorsIan Mann, Satyanarayan Barik, Marie Wintrebert-Fouquet, Josh Brown, Paul Dunnigan
Life of this patent
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Abstract
A plasma generator is described which employs a partial PBN liner not only to minimise the loss of energetic gas species during film formation but also to reduce boron impurity levels introduced into the growing film relative to the use of a complete PBN liner. The use of such a plasma generator in a film forming apparatus and method of forming a film is also described.
Claims20
A plasma generator comprising:
- (a) a plasma tube having a gas inlet formed in a first end of the plasma tube and a plasma outlet formed in a second end of the plasma tube;
- (b) an ionising source, in the form of an RF coil, adjacent the plasma tube and thereby defining a first region thereof, and to expose that first region to an electromagnetic field to generate active plasma species, the first region beginning adjacent the first end of the plasma tube;
- and
- (c) an exposed pyrolytic boron nitride liner lining the inner walls of the plasma tube within a second region thereof, the second region being between the first region and the second end of the plasma tube;
- and
- wherein the pyrolytic boron nitride liner is spaced from a lowermost extent of the ionising source closest to the plasma outlet, by a distance of 10-75 mm.
3 more elements
An apparatus for depositing a group III metal nitride film on a substrate, the apparatus comprising:
- (a) a plasma generator to generate a nitrogen plasma from a nitrogen source the plasma generator comprising:
- (i) a plasma tube having a gas inlet formed in a first end of the plasma tube and a plasma outlet formed in a second end of the plasma tube;
- (ii) an ionising source adjacent the plasma tube and thereby defining a first region thereof, and to expose that first region to an electromagnetic field to generate active plasma species, the first region beginning adjacent the first end of the plasma tube;
- (iii) an exposed pyrolytic boron nitride liner located adjacent the inner walls of the plasma tube within a second region thereof, the second region being between the first region and the second end of the plasma tube, wherein the pyrolytic boron nitride liner is spaced from a lowermost extent of the ionising source closest to the plasma outlet, by a distance of 10-75 mm;
- (b) a growth chamber in which to react a reagent comprising a group III metal with active nitrogen species derived from the nitrogen plasma so as to deposit a group III metal nitride on the substrate;
- and
- (c) a plasma inlet on the growth chamber to facilitate passage of nitrogen plasma from the plasma generator into the growth chamber.
4 more elements
A method of generating a plasma including the steps of:
- (a) providing a plasma generator comprising a plasma tube having a gas inlet formed in a first end of the plasma tube and a plasma outlet formed in a second end of the plasma tube, an ionizing source, in the form of an RF coil, adjacent the plasma tube and thereby defining a first region thereof, and to expose that first region to an electromagnetic field to generate active plasma species, the first region beginning adjacent the first end of the plasma tube, and an exposed pyrolytic boron nitride liner lining the inner walls of the plasma tube within a second region thereof, the second region being between the first region and the second end of the plasma tube, wherein the pyrolytic boron nitride liner is spaced from a lowermost extent of the ionising source closest to the plasma outlet, by a distance of 10-75 mm;
- (b) supplying a feed gas through the gas inlet;
- and
- (c) exposing the gas to an electromagnetic field within the first region, to thereby generate a plasma.
1 more element
A plasma generator comprising:
- (a) a cylindrical plasma tube having a gas inlet formed in a first end of the cylindrical plasma tube and a plasma outlet formed in a second end of the cylindrical plasma tube;
- (b) an ionising source, in the form of an RF coil, adjacent the cylindrical plasma tube and thereby defining a first cylindrical region thereof, and to expose that first cylindrical region to an electromagnetic field to generate active plasma species, the first cylindrical region beginning adjacent the first end of the cylindrical plasma tube;
- and
- (c) an exposed pyrolytic boron nitride liner lining the inner walls of the cylindrical plasma tube within a second cylindrical region thereof, the exposed pyrolytic boron nitride liner having a diameter substantially conforming to an inner diameter of the cylindrical plasma tube, the second cylindrical region being between the first cylindrical region and the second end of the cylindrical plasma tube, wherein:
- the pyrolytic boron nitride liner is spaced from a lowermost extent of the ionising source closest to the plasma outlet, by a distance of 10-75 mm;
- and
- the cylindrical plasma tube is cylindrical along its length between the first end and second end.
4 more elements
Dependencies are inferred from the claim text.