Method for determining the height of a layer of carbon nanotubes

Patent metadata

Field	Value
Publication number	US-2020103221-A1
Application number	US-201916583309-A
Country	US
Kind code	A1
Filing date	Sep 26, 2019
Priority date	Sep 28, 2018
Publication date	Apr 2, 2020
Grant date	—

Abstract

A method for measuring the height of a forest of carbon nanotubes, containing:
a) providing a substrate having a growth area containing at least one measurement zone containing a growth zone and a sterile zone, the growth zone being defined by a segment of the substrate containing a growth catalyst of the nanotubes, and b) growing catalytically by CVD the forest of nanotubes in the growth zone,

wherein, at least in step b) contains:
irradiating the measurement zone with an incident light beam; measuring, at various times, the intensity of the beam reflected by the measurement zone; and determining the height of the forest of nanotubes from the reflected-beam intensities measured at the various times.

First claim

1 : A method for measuring a height of a forest of carbon nanotubes, the method comprising:
a) providing a substrate having a growth area, the growth area comprising a measurement zone comprising a growth zone and a zone sterile to growth of the carbon nanotubes, called a “virgin” zone, and the growth zone being defined by a segment of the substrate comprising a catalyst of the growth of the carbon nanotubes, and b) growing catalytically, in a chemical-vapour-deposition reactor, the forest of carbon nanotubes in the growth zone, wherein the growing comprises
irradiating the measurement zone by means of an incident light beam;
measuring, at various times, an intensity of the incident light beam reflected by the measurement zone; and
determining the height of the forest of carbon nanotubes from reflected-beam intensities measured at the various times.

2 : The method according to claim 1 , wherein the virgin zone is defined by another segment of the substrate that absorbs less and/or reflects more the incident light beam than the forest of carbon nanotubes.

3 : The method according to claim 1 , wherein the substrate comprises a carrier and a coating partially covering the carrier, and
the coating comprises the catalyst.

4 : The method according to claim 3 , wherein the coating comprises a first face placed facing the carrier and a second face opposite the first face, and
the growth zone is defined by the second face.

5 : The method according to claim 1 , wherein the substrate comprises a carrier, and
the virgin zone is defined by a segment of the carrier made of a material that is inert with respect to the growth of the carbon nanotubes.

6 : The method according to claim 1 , wherein the substrate comprises a carrier and a coating partially covering the carrier, and
the virgin zone is at least partially defined by a segment of a face of the carrier that is complementary to a segment of the face of the carrier covered by the coating.

7 : The method according to claim 1 , wherein the growth zone and the virgin zone define a measurement pattern, the measurement zone being defined by a regular repetition, in at least one direction of the measurement pattern.

8 : The method according to claim 1 , wherein the growth zone and the virgin zone each has a rectilinear strip shape.

9 : The method according to claim 1 , wherein the growth zone has a width of between 30 μm and 500 μm, and/or the virgin zone has a width of between 30 μm and 10000 μm.

10 : The method according to claim 1 , wherein the growth zone and the virgin zone are perpendicular to a plane containing a direction of propagation of the incident light beam.

11 : The method according to claim 1 , wherein the incident light beam is a parallel laser beam.

12 : The method according to claim 1 , wherein an angle of incidence (α i ) of the incident light beam is larger than 0°.

13 : The method according to claim 1 , wherein, during at least some of the growth of the forest of carbon nanotubes, the height of the forest of carbon nanotubes increases as a function of decrease in an intensity of reflected beam.

14 : The method according to claim 15 , wherein, during at least some of the growth of the forest of carbon nanotubes, the height of the forest of carbon nanotubes increases in a continuously monotonic way linearly as a function of the decrease in the intensity of the reflected beam.

15 : The method according to claim 13 , wherein, during at least some of the growth of the forest of carbon nanotubes, the height of the forest of carbon nanotubes increases, in a continuously monotonic way, as a function of the decrease in the intensity of the reflected beam.

Assignees

• Commissariat Energie Atomique
• Centre Nat Rech Scient
• Univ Claude Bernard Lyon

Inventors

• Ramos Raphael
• David Lorie
• Dijon Jean

Classifications

• C01B32/16

  Preparation · CPC title

• C23C16/26

  Deposition of carbon only · CPC title

• G01B11/0608 Primary

  Height gauges · CPC title

• C01B2202/08

  Aligned nanotubes · CPC title

• C23C16/4583

  the substrate being supported substantially horizontally · CPC title