Interrupted method for producing multilayered polycrystalline diamond films

Claim 2

A chemical vapor deposition method for producing a coated substrate product comprising: placing a parent substrate comprising a material selected from the group consisting of a single crystal, polycrystalline materials, metal, metal alloy, mixture of metals, ceramic materials and mixtures thereof into a hot filament chemical vapor deposition reactor; chemically vapor depositing a first polycrystalline diamond layer onto said parent substrate using a hot filament during the first of at least two cycles; cooling the coated substrate after the first cycle to a temperature substantially below the deposition temperature; and chemically vapor depositing at least a second polycrystalline diamond layer onto said coated substrate using a hot filament.

Claim 3

The method of claim 1 wherein said coated substrate is cooled to a temperature below about 100° C. prior to applying the second polycrystalline diamond layer.

Claim 4

The method of claim 1 wherein said coated substrate is cooled to substantially room temperature prior to applying the second polycrystalline diamond layer.

Claim 5

The method of claim 1 wherein the length of time of each cycle is at least three hours.

Claim 6

The method of claim 1 wherein at least three separate polycrystalline diamond layers are chemical vapor deposited during at least three cycles in which each cycle is separated by a cool-down step.

Claim 7

The method of claim 5 wherein the total thickness of said polycrystalline diamond layers is at least about 12 μm.

Claim 8

The method of claim 1 wherein the total thickness of said polycrystalline diamond layers is in the range of about 12 μm to about 250 μm.

Claim 9

The method of claim 1 wherein the total thickness of said polycrystalline diamond layers is in the range of about 20 μm to about 130 μm.

Claim 10

The method of claim 1 wherein said separate polycrystalline diamond layers are each chemical vapor deposited at deposition temperatures in the range of 650° to 825° C.

Claim 11

The method of claim 1 wherein said polycrystalline diamond layers have electrical resistivity greater than 10 6 ohm-cm.

Claim 12

The method of claim 1 wherein said parent substrate is molybdenum.

Claim 13

The method of claim 11 wherein molybdenum carbide is formed in situ between said parent substrate and said first polycrystalline diamond layer.

Claim 14

The method of claim 1 wherein said parent substrate is silicon.

Claim 15

The method of claim 13 wherein silicon carbide is formed in situ between said parent substrate and said first polycrystalline diamond layer.

Claim 16

The method of claim 1 wherein said coated substrate is cooled to a temperature below 600° C. between cycles.

Claim 17

The method of claim 1 wherein said coated substrate after applying said second polycrystalline diamond layer is cooled to substantially room temperature.

Claim 18

The method of claim 1 wherein the deposition temperature used in all the cycles is essentially the same.

Claim 19

The method of claim 1 wherein the deposition temperature used in the second cycle is lower than the first cycle.

Claim 20

The method of claim 1 wherein the deposition temperature used in the second cycle is higher than the first cycle.

Claim 21

The method of claim 1 wherein said polycrystalline diamond layer has at least partially ordered crystal orientation in at least two planes in comparison to industrial grade diamond crystals.

Claim 22

The method of claim 20 wherein said polycrystalline diamond layer has an enhanced crystal orientation in the (220) and (400) directions relative to the (111) direction.

Claim 23

The method of claim 21 wherein said polycrystalline diamond layer further includes an enhanced crystal orientation in the (311) direction relative to the (111) direction.

Claim 24

The method of claim 20 wherein said polycrystalline diamond layer has an enhanced crystal orientation in the (311) and (400) directions relative to the (111) direction.

Claim 25

A chemical vapor deposition method for fabricating a coated substrate product comprising: placing a parent substrate comprising a material selected from the group consisting of a single crystal, polycrystalline materials, metal, metal alloy, mixture of metals, ceramic materials and mixtures thereof into a hot filament chemical vapor deposition reactor; heating said parent substrate during a first cycle of at least one set of two cycles to a temperature in the range of about 650° to 825° C. by means of a filament electrically charged to a temperature in the range of about 1800° to 2250° C.; chemically vapor depositing during the first cycle of at least two cycles a first polycrystalline diamond layer having a thickness in the range of about 2 to about 10 μm onto the heated substrate by passing a gaseous mixture of hydrocarbons and hydrogen into said reactor for a period of at least three hours; passing an inert gas over said coated substrate while said filament remains electrically charged for a period of time to purge said reactor of said gaseous mixture during the commencement of a cool-down step; cooling said coated substrate by removing the charge from said filament and continuing the passing of the inert gas over the substrate until the temperature has reached substantially room temperature during said cool-down step; chemically vapor depositing during a second cycle of at least two cycles a second polycrystalline diamond layer having a thickness in the range of about 2 to about 10 μm onto said first layer for a period of at least an additional three hours; and recovering a substrate coated with a plurality of polycrystalline diamond layers exhibiting uniform microstructure and a high electrical resistivity.

Claim 26

A chemical vapor deposition method for fabricating a coated substrate product comprising: placing a parent substrate comprising a material selected from the group consisting of a single crystal, polycrystalline materials, metal, metal alloy, mixture of metals, ceramic materials and mixtures thereof into a hot filament chemical vapor deposition reactor; heating said parent substrate during a first cycle of at least one set of two cycles to a temperature in the range of about 650° to 825° C. by means of a filament electrically charged to a temperature in the range of about 1800° to 2250° C.; chemically vapor depositing during the first cycle of at least two cycles a first polycrystalline diamond layer having a thickness in the range of about 2 to about 10 μm onto the heated substrate by passing a gaseous mixture of hydrocarbons and hydrogen into said reactor for a period of at least three hours; passing an inert gas over said coated substrate while said filament remains electrically charged for a period of time to purge said reactor of said gaseous mixture during the commencement of a cool-down step; cooling said coated substrate by removing the charge from said filament and continuing the passing of the inert gas over the substrate until the temperature has reached substantially room temperature during said cool-down step; chemically vapor depositing during a second cycle of at least two cycles a second polycrystalline diamond layer having a thickness in the range of about 2 to about 10 μm onto said first layer for a period of at least an additional three hours; and recovering a substrate coated with a plurality of polycrystalline diamond layers exhibiting uniform microstructure and a high electrical resistivity.

Claim 27

The method of claim 24 wherein at least 3 cycles are used to deposit at least 3 polycrystalline diamond layers and in which each cycle is separated by a cool-down step.

Claim 28

The method of claim 25 wherein the length of time of each cycle is at least three hours.

Claim 29

The method of claim 24 wherein the total thickness of said polycrystalline diamond layers is in the range of about 12 μm to about 250 μm.

Claim 30

The method of claim 24 wherein the total thickness of said polycrystalline diamond layers is about 20 μm to about 130 μm.

Claim 31

The method of claim 24 wherein the deposition rate for each of said polycrystalline diamond layers is generally about 0.5 μm per hour.

Claim 32

The method of claim 24 wherein said polycrystalline diamond layers have electrical resistivity greater than 10 6 ohm-cm.

Claim 33

The method of claim 24 wherein said parent substrate is molybdenum.

Claim 34

The method of claim 31 wherein 2 μm to 5 μm of molybdenum carbide is formed in situ between said parent substrate and said first polycrystalline diamond layer.

Claim 35

The method of claim 24 wherein said parent substrate is silicon.

Claim 36

The method of claim 33 wherein up to 1 μm of silicon carbide is formed in situ between said parent substrate and said first polycrystalline diamond layer.

Claim 37

The method of claim 24 wherein said coated substrate is cooled to a temperature below about 100° C. between cycles.

Claim 38

The method of claim 24 wherein said coated substrate is cooled to substantially room temperature.

Claim 39

The method of claim 24 wherein the deposition temperature used in all the cycles is essentially the same.

Claim 40

The method of claim 24 wherein the deposition temperature used in the second cycle is lower than the first cycle.

Claim 41

The method of claim 24 wherein the deposition temperature used in the second cycle is higher than the first cycle.

Claim 42

The method of claim 24 wherein said polycrystalline diamond layer has an enhanced crystal orientation in at least two planes in comparison to industrial grade diamond crystals.

Claim 43

The method of claim 40 wherein said polycrystalline diamond layer has an enhanced crystal orientation in the (220) and (400) directions relative to the (111) direction.

Claim 44

The method of claim 41 wherein said polycrystalline diamond layer further includes an enhanced crystal orientation in the (311) direction relative to the (111) direction.

Claim 45

The method of claim 40 wherein said polycrystalline diamond layer has an enhanced crystal orientation in the (311) and (400) directions relative to the (111) direction.