Energy dependence of vacuum-ultraviolet-induced radiation damage to electronic materials

Dielectric charging plays a key role in processing damage of semiconductor devices. VUV radiation with energies in the range of 4-30 eV can induce charge on electronic materials. Radiation charging of Si wafers coated with 3000A of Si/sub 3/N/sub 4/ from synchrotron VUV exposure with photon fluxes in the range of 10/sup 9/-10/sup 13/ photons/sec cm/sup -2/ were measured with a Kelvin probe. The photoemission current and substrate voltage were monitored during each exposure. The integral of photoemission current was compared to the net charge measured with the Kelvin probe for VUV photon energies between 7-21 eV. The net charge induced on the dielectric results from both photoemission (which saturates for long exposure times) as well as from charge carriers generated within the dielectric. Since the threshold photon energy for photoemission is higher than that for electron-hole pair production, it is seen that photoemission can be minimized if the photon energies are below the threshold energy.

[1]  Jan Ackaert,et al.  Charging induced damage by photoconduction through thick inter metal dielectrics , 2003, Microelectron. Reliab..

[2]  J. L. Shohet,et al.  Measuring vacuum ultraviolet radiation-induced damage , 2003 .

[3]  A. Scarpa,et al.  Effect of charge transport through silicon nitride on thin gate oxide reliability , 2002 .

[4]  J. Shohet,et al.  Photoemission and conduction currents in vacuum ultraviolet irradiated aluminum oxide , 2002 .

[5]  J. McVittie,et al.  Synchrotron radiation-induced surface-conductivity of SiO2 for modification of plasma charging , 2000 .

[6]  T. W. Hamilton,et al.  Absolute Intensities of the Vacuum Ultraviolet Spectra in a Metal-Etch Plasma Processing Discharge , 1999 .

[7]  J. Shohet,et al.  Plasma vacuum ultraviolet emission in an electron cyclotron resonance etcher , 1999 .

[8]  I. D. Baikie,et al.  Low cost PC based scanning Kelvin probe , 1998 .

[9]  F. Shimura,et al.  Interface traps creation by sub‐band gap irradiation in silicon dioxide on silicon without applied electric field , 1996 .

[10]  K. S. Chari,et al.  Photo-processing of silicon nitride , 1995 .

[11]  K. Cheung,et al.  Charging damage from plasma enhanced TEOS deposition , 1995, IEEE Electron Device Letters.

[12]  R. Hummel,et al.  Comparison of anodically etched porous silicon with spark-processed silicon , 1995 .

[13]  C. Ling.  Trap generation at Si/SiO2 interface in submicrometer metal‐oxide‐semiconductor transistors by 4.9 eV ultraviolet irradiation , 1994 .

[14]  T. Tatsumi,et al.  Radiation Damage of SiO2 Surface Induced by Vacuum Ultraviolet Photons of High-Density Plasma , 1994 .

[15]  D. Buchanan,et al.  Vacuum ultraviolet radiation damage in electron cyclotron resonance and reactive ion etch plasmas , 1991 .

[16]  Keizo Suzuki,et al.  Mechanism of Radiation Damage in SiO2/Si Induced by vuv Photons , 1989 .

[17]  G. F. Derbenwick,et al.  Vacuum Ultraviolet Radiation Effects in SiO2 , 1971 .

[18]  W. A. Zisman,et al.  A NEW METHOD OF MEASURING CONTACT POTENTIAL DIFFERENCES IN METALS , 1932 .

[19]  Lord Kelvin,et al.  V. Contact electricity of metals , 1898 .

[20]  I. Boyd,et al.  Photo-induced large area growth of dielectrics with excimer lamps , 2000 .

[21]  T. P. Ma,et al.  Ionizing radiation effects in MOS devices and circuits , 1989 .