A coloured single crystal CVD synthetic diamond material comprising: a plurality of layers, wherein the plurality of layers includes at least two sets of layers which differ in terms of their defect composition and colour, wherein defect type, defect concentration, and layer thickness for each of the at least two sets of layers is such that if the coloured single crystal CVD diamond material is fabricated into a round brilliant cut diamond comprising a table and a culet, and having a table to culet depth greater than 1 mm, the round brilliant cut diamond comprises a uniform colour as viewed by naked human eye under standard ambient viewing conditions in at least a direction through the table to the culet.

The invention relates to a device (1) and method for applying a carbon layer, in particular a diamond layer, to a substrate (2, 2a) by means of chemical vapour deposition, comprising a deposition chamber (3) into which a process gas, in particular molecular hydrogen and/or a mixture of molecular hydrogen and a carbon-containing gas, such as methane can be supplied, wherein a gas inlet and gas activation element (7) is provided in the form of a hollow body with a flow channel (7b) for the process gas, a wall (7a) surrounding the flow channel (7b), and an outlet opening (16) feeding from the flow channel (7b) into the deposition chamber (3), and a heating device (8) is provided for heating the wall (7a) of the gas inlet and gas activation element (7).

A vapor phase growth apparatus according to an embodiment includes a reaction chamber; a substrate holder having a holding wall capable holding an outer periphery of the substrate; a process gas supply part provided above the reaction chamber, the process gas supply part having a first region supplying a first process gas and a second region around the first region supplying a second process gas having a carbon/silicon atomic ratio higher than that of the first process gas, an inner peripheral diameter of the second region being 75% or more and 130% or less of a diameter of the holding wall; a sidewall provided between the process gas supply part and the substrate holder, an inner peripheral diameter of the sidewall being 110% or more and 200% or less of an outer peripheral diameter of the second region; a first heater; a second heater; and a rotation driver.

A method of manufacturing a group-III nitride crystal includes: preparing a seed substrate; and supplying a group-III element oxide gas and a nitrogen element-containing gas at a supersaturation ratio (P.sup.o/P.sup.e) greater than 1 and equal to or less than 5, then, growing a group-III nitride crystal on the seed substrate, wherein the P.sup.o is a supply partial pressure of the group-III element oxide gas, and the P.sup.e is an equilibrium partial pressure of the group-III element oxide gas.

A method for manufacturing diamond substrate of using source gas containing hydrocarbon gas and hydrogen gas to form diamond crystal on an underlying substrate by CVD method, to form a diamond crystal layer having nitrogen-vacancy centers in at least part of the diamond crystal, nitrogen or nitride gas is mixed in the source gas, wherein the source gas is: 0.005 volume % or more and 6.000 volume % or less of the hydrocarbon gas; 93.500 volume % or more and less than 99.995 volume % of the hydrogen gas; and 5.0×10.sup.−5 volume % or more and 5.0×10.sup.−1 volume % or less of the nitrogen gas or the nitride gas, and the diamond crystal layer having the nitrogen-vacancy centers is formed. A method for manufacturing a diamond substrate to form an underlying substrate, a diamond crystal having a dense nitrogen-vacancy centers (NVCs) with an orientation of NV axis by performing the CVD.

Disclosed is a method for growing a high-quality heteroepitaxial β-Ga2O3 crystal by specifically using low-pressure chemical vapor deposition (LPCVD) method in the field of chemical vapor deposition, wherein said method includes the process steps of; preparing the substrate having hexagonal surfaces cut in different directions with inclinations such that the inclination angle is in a range between 2° and 10°; physically carrying the vapor obtained from Gallium heated in the second zone to the pump/sample by means of Argon gas; driving oxygen into the system with a separate ceramic or refractory metal tube and vertically transferring it onto the surface of the sample directly over the substrate; creating the core layer of β-Ga2O3 on the surface such that the ratio of Ga:O surface atoms on the growing surface is in a range between 10:1 and 1:10 so as to ensure that the surface atoms of Ga and O create the β-Ga2O3 crystal on the heated substrate; growing the core region of β-Ga2O3 at a thickness between 5 nm-2000 nm and at the growth rate between 10 nm/h-500 nm/h; maintaining the growing process on the core layer created in the previous step such that the β-Ga2O3 growth rate is in a range between 100 nm/h and 10 μm/h.

An apparatus for forming semiconductor films can include a horizontal flow reactor including an upper portion and a lower portion that are moveably coupled to one another so as to separate from one another in an open position and so as to mate together in a closed position to form a reactor chamber. A central injector column can penetrate through the upper portion of the horizontal flow reactor into the reactor chamber, the central injector column configured to allow metalorganic precursors into the reactor chamber in the closed position. A heated metalorganic precursor line can be coupled to the central injector column and configured to heat a low vapor pressure metalorganic precursor vapor contained in the heated metalorganic precursor line upstream of the central injector column to a temperature range between about 70 degrees Centigrade and 200 degrees Centigrade and a processor circuit can be operatively coupled to the heated metalorganic precursor line and configured to maintain a temperature of the low vapor pressure metalorganic precursor vapor within the temperature range.

A method for producing nanostructures having a metal oxide shell, carried by a top face of a substrate whose greatest dimension is greater than or equal to 100 mm by MOCVD metalorganic chemical vapour deposition, including successive steps carried out in a reactor configured for MOCVD deposition of nucleation and growth. The nucleation step includes forming non-contiguous metal nuclei by depositing a metal by MOCVD using a metalorganic precursor on the top face of the substrate and oxidising the metal of the metal nuclei, to form oxidised nuclei and ensure stabilisation of the nuclei. The growth step includes depositing a metal by MOCVD using the metalorganic precursor, to form non-contiguous nanostructures by growth of the oxidised nanostructures, and oxidising the deposited metal of the nanostructures formed in the nucleation to form oxidised nanostructures.

Some examples herein provide a method of forming a doped silicon germanium layer. The method may include simultaneously exposing a substrate to (a) a silicon precursor, (b), a germanium precursor, (c) a boron precursor, and (d) a heteroleptic gallium precursor. The heteroleptic gallium precursor may include (i) at least one straight chain alkyl group in which a terminal carbon is directly bonded to gallium, and (ii) at least one tertiary alkyl group in which a tertiary carbon is directly bonded to gallium. The method may include reacting the silicon precursor, the germanium precursor, the boron precursor, and the heteroleptic gallium precursor to form a silicon germanium layer on the substrate that is doped with boron and gallium.

The disclosure relates to a method for growing a semiconductor assembly. The method includes the steps of providing a silicon substrate and growing two metal nitride layers, each metal nitride layer being grown by means of a metal target and a plasma. For the second metal nitride layer a higher hydrogen content is used, allowing for better crystal quality than in known methods. The disclosure further relates to a semiconductor assembly that is produced accordingly.