AVS 45th International Symposium
    Thin Films Division Thursday Sessions
       Session TF-ThM

Paper TF-ThM3
Field Emission and Photo Emission from Si Micro Tip Arrays Coated with Bias-Grown Diamond Films

Thursday, November 5, 1998, 9:00 am, Room 310

Session: Thin Films for Flat Panel Applications
Presenter: M.Q. Ding, Argonne National Laboratory
Authors: M.Q. Ding, Argonne National Laboratory
A.R. Krauss, Argonne National Laboratory
O. Auciello, Argonne National Laboratory
D.M. Gruen, Argonne National Laboratory
T.D. Corrigan, Argonne National Laboratory
M.E. Kordesch, Ohio University
D. Temple, MCNC
D. Palmer, MCNC
G.E. McGuire, MCNC
Correspondent: Click to Email
A considerable improvement in the properties of field and photoelectron emission from ungated Si micro tip arrays coated with bias-grown diamond thin films is reported. Prior to loading into a MPCVD reactor (ASTeX PDS-17), the microtip arrays were ultrasonically treated in a 0.1 µmm diamond suspension. Diamond films were grown in a CH@sub 4@-H@sub 2@-N@sub 2@ plasma at a substrate temperature of 800 °C and a negative bias of -150 V. The film had a complete coverage over the tip arrays as observed from secondary electron microscopy (SEM). Electron emission characteristics were measured in two different systems: field emission current-field (IF) measuring apparatus and photoelectron emission microscopy (PEEM). IF measurements showed a very low turn-on electric field with a threshold fields of 1.5 V/µmm (vs 40 V/µmm for uncoated tip arrays), and a current density of 1 mA/cm2 at around 4 V/µmm. In the PEEM studies, UV light from a mercury arc lamp was used to excite photoelectrons. While the lamp was on, the PEEM revealed a uniform and bright photoelectron emission image of the coated tip arrays in contrast to that of the uncoated arrays. When the lamp was off, stable field electron emission images of the coated tip arrays were also seen with a reasonable brightness at an electric field 5.6 V/µmm, whereas images of uncoated arrays could hardly be discerned and emission was unstable. Such a remarkable improvement in both field emission and photoemission properties, as compared to those of the uncoated arrays, indicates that the microtip arrays coated with bias-grown diamond films are promising for applications such as flat panel displays. A possible mechanism for the improvement will be discussed. This work is supported by the U.S. Department of Energy, BES-Materials Sciences, under Contract W-31-109-ENG-39.