Studies of field emission from bias-grown diamond thin films

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Abstract

We have investigated the field emission properties of diamond films grown under substrate bias conditions in a microwave plasma chemical vapor deposition system, with a substrate temperature of 800C, microwave power of 600 W, and a total pressure of 11 Torr. One group of films was grown with a substrate bias of -100 V in gas mixtures of 1% N2 and 1%-20% CH4 in H2, while a second group of films was grown with a substrate bias ranging from +100 to -150 V in a gas mixture of 1%N2-10%CH4-89%H2. The field emission performance in terms of threshold field and emission current improved considerably as a function of increasing CH4 concentration and negative bias voltage. Ultraviolet Raman analysis showed that the field emission enhancement resulting from an increase in CH4 concentration from 1% to 5% correlates with a decrease in the sp3 bonding character in the diamond film. The dependence of field emission on negative bias voltage appears to be correlated with ion bombardment-induced damage in the film during growth. The scanning electron microscopy image of the film grown with -150 V bias showed: smaller surface topographic features as compared to films grown under 0 and +100 V bias. The film grown with a bias of -150 V showed the lowest threshold field (∼2.0 V/μm) corresponding to an emission current density of 12.7 μA/cm2. J vs E0 measurements across a length of 40 mm over the film showed a uniform threshold field (2.0±0.55 V/μm). The film grown with a positive bias (+100 V) showed a relatively poor field emission performance.

Original languageEnglish
Pages (from-to)705-709
Number of pages5
JournalJournal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures
Volume17
Issue number2
Publication statusPublished - 1999

Fingerprint

Diamond films
Field emission
field emission
diamonds
Thin films
thin films
Substrates
Bias voltage
Gas mixtures
diamond films
Microwaves
thresholds
gas mixtures
Film growth
Ion bombardment
microwaves
Chemical vapor deposition
electric potential
Current density
bombardment

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Physics and Astronomy (miscellaneous)
  • Surfaces and Interfaces

Cite this

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title = "Studies of field emission from bias-grown diamond thin films",
abstract = "We have investigated the field emission properties of diamond films grown under substrate bias conditions in a microwave plasma chemical vapor deposition system, with a substrate temperature of 800C, microwave power of 600 W, and a total pressure of 11 Torr. One group of films was grown with a substrate bias of -100 V in gas mixtures of 1{\%} N2 and 1{\%}-20{\%} CH4 in H2, while a second group of films was grown with a substrate bias ranging from +100 to -150 V in a gas mixture of 1{\%}N2-10{\%}CH4-89{\%}H2. The field emission performance in terms of threshold field and emission current improved considerably as a function of increasing CH4 concentration and negative bias voltage. Ultraviolet Raman analysis showed that the field emission enhancement resulting from an increase in CH4 concentration from 1{\%} to 5{\%} correlates with a decrease in the sp3 bonding character in the diamond film. The dependence of field emission on negative bias voltage appears to be correlated with ion bombardment-induced damage in the film during growth. The scanning electron microscopy image of the film grown with -150 V bias showed: smaller surface topographic features as compared to films grown under 0 and +100 V bias. The film grown with a bias of -150 V showed the lowest threshold field (∼2.0 V/μm) corresponding to an emission current density of 12.7 μA/cm2. J vs E0 measurements across a length of 40 mm over the film showed a uniform threshold field (2.0±0.55 V/μm). The film grown with a positive bias (+100 V) showed a relatively poor field emission performance.",
author = "Chang, {Robert P. H.}",
year = "1999",
language = "English",
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pages = "705--709",
journal = "Journal of Vacuum Science & Technology B: Microelectronics Processing and Phenomena",
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AU - Chang, Robert P. H.

PY - 1999

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N2 - We have investigated the field emission properties of diamond films grown under substrate bias conditions in a microwave plasma chemical vapor deposition system, with a substrate temperature of 800C, microwave power of 600 W, and a total pressure of 11 Torr. One group of films was grown with a substrate bias of -100 V in gas mixtures of 1% N2 and 1%-20% CH4 in H2, while a second group of films was grown with a substrate bias ranging from +100 to -150 V in a gas mixture of 1%N2-10%CH4-89%H2. The field emission performance in terms of threshold field and emission current improved considerably as a function of increasing CH4 concentration and negative bias voltage. Ultraviolet Raman analysis showed that the field emission enhancement resulting from an increase in CH4 concentration from 1% to 5% correlates with a decrease in the sp3 bonding character in the diamond film. The dependence of field emission on negative bias voltage appears to be correlated with ion bombardment-induced damage in the film during growth. The scanning electron microscopy image of the film grown with -150 V bias showed: smaller surface topographic features as compared to films grown under 0 and +100 V bias. The film grown with a bias of -150 V showed the lowest threshold field (∼2.0 V/μm) corresponding to an emission current density of 12.7 μA/cm2. J vs E0 measurements across a length of 40 mm over the film showed a uniform threshold field (2.0±0.55 V/μm). The film grown with a positive bias (+100 V) showed a relatively poor field emission performance.

AB - We have investigated the field emission properties of diamond films grown under substrate bias conditions in a microwave plasma chemical vapor deposition system, with a substrate temperature of 800C, microwave power of 600 W, and a total pressure of 11 Torr. One group of films was grown with a substrate bias of -100 V in gas mixtures of 1% N2 and 1%-20% CH4 in H2, while a second group of films was grown with a substrate bias ranging from +100 to -150 V in a gas mixture of 1%N2-10%CH4-89%H2. The field emission performance in terms of threshold field and emission current improved considerably as a function of increasing CH4 concentration and negative bias voltage. Ultraviolet Raman analysis showed that the field emission enhancement resulting from an increase in CH4 concentration from 1% to 5% correlates with a decrease in the sp3 bonding character in the diamond film. The dependence of field emission on negative bias voltage appears to be correlated with ion bombardment-induced damage in the film during growth. The scanning electron microscopy image of the film grown with -150 V bias showed: smaller surface topographic features as compared to films grown under 0 and +100 V bias. The film grown with a bias of -150 V showed the lowest threshold field (∼2.0 V/μm) corresponding to an emission current density of 12.7 μA/cm2. J vs E0 measurements across a length of 40 mm over the film showed a uniform threshold field (2.0±0.55 V/μm). The film grown with a positive bias (+100 V) showed a relatively poor field emission performance.

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