Plasma damage effects on low-k porous organosilicate glass

Journal Article · Sun Nov 14 23:00:00 EST 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3506523· OSTI ID:21476611

Ren, H; Shohet, J L ^[1]; Antonelli, G A ^[2]; Nishi, Y ^[3]

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1. Department of Electrical and Computer Engineering, Plasma Processing and Technology Laboratory, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)
2. Novellus Systems, Tualatin, Oregon 97062 (United States)
3. Stanford University, Stanford, California 94305 (United States)

Damage induced in low-k porous organosilicate glass (SiCOH) dielectric films by exposure to an electron cyclotron resonance (ECR) plasma was investigated. The effects of charged-particle bombardment and vacuum ultraviolet radiation were separated. Flux measurements showed that the ECR plasma has a greater photon flux in the vacuum ultraviolet (VUV) range than in the UV range. Damage was measured by examining the surface potential and capacitance-voltage characteristics after exposure. It was found that during argon ECR plasma processing, 75% of the charge accumulation comes from ions at the surface, while 25% of the charge accumulation occurs from charge trapped within the bulk of the dielectric film. The charge accumulation can be modified by changing the bias voltage of the wafer chuck. UV exposure was shown to repair both sources of damage. Fourier transform infrared (FTIR) spectroscopy results showed no significant change except for Si-(CH{sub 3}){sub x} bonds. It was found that both charged-particle bombardment and radiation from the ECR plasma damage these bonds. Ellipsometric measurements showed that both the dielectric thickness and the dielectric constant changed during plasma exposure. In addition, both plasma-induced swelling and UV-exposure shrinking effects were observed. The plasma-induced swelling occurs at the surface of the dielectric without changing the porosity of the dielectric, while UV-induced shrinking changes the porosity significantly.

• OSTI ID: 21476611
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 108; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BEAMS
CYCLOTRON RESONANCE
DEFORMATION
DIELECTRIC MATERIALS
DIELECTRIC PROPERTIES
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
ELECTRON CYCLOTRON-RESONANCE
FAR ULTRAVIOLET RADIATION
FILMS
FOURIER TRANSFORMATION
GLASS
INFRARED SPECTRA
INTEGRAL TRANSFORMATIONS
ION BEAMS
IRRADIATION
MATERIALS
PERMITTIVITY
PHYSICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
PLASMA
POROUS MATERIALS
POTENTIALS
RADIATION EFFECTS
RADIATIONS
RESONANCE
SILICON COMPOUNDS
SPECTRA
SPECTROSCOPY
SURFACE POTENTIAL
SURFACES
SWELLING
THIN FILMS
TRANSFORMATIONS
TRAPPING
ULTRAVIOLET RADIATION