Plasma Technology  


graph stress vs frequency split


SEM showing SiO2 PECVD with good step coverage

SiO2 PECVD
(OPT application lab)

Plasmalab 80 Plus photo
Plasmalab 80 Plus

Stress Control for Si3N4 and SiO2 PECVD


Strain control of films is of very high importance for the fabrication of microstructures by bulk and surface micromachining. The key parameter to control the material strain of films deposited by Plasma Enhanced Chemical Vapour Deposition (PECVD) is the plasma excitation frequency, which influences the ion bombardment energy. The behaviour of the mechanical stress of thin dielectric films e.g. silicon nitride and silicon dioxide using frequency interlacing of 130 KHz (low frequency) and 13,56 MHz (high frequency) was studied. Stress control was achieved between tensile 40 MPa) and compressive (+120 MPa) approaching zero stress as close as 5 MPa.

PECVD scetch/ 4 kB

PECVD

 

with kind permission

Dr.-Ing. J. Daleiden, A. Tarraf, Prof. H. Hillmer
Head of III/V-Technology
Institute of Microstructure Technology and Analytics
Uni Kassel

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