Low-stress silicon carbonitride for the machining of high-frequency nanomechanical resonators

The synthesis of silicon carbonitride by low-temperature plasma-enhanced chemical vapor deposition and the machining of nanomechanical resonators in this material are reported. Films with thickness of 1μm, 200nm, and 50nm were deposited using ammonia, nitrogen, and diethylsilane as precursors. X-ray photoelectron spectroscopy indicated that usage of higher NH3:DES gas flow ratios results in higher nitrogen and low carbon contents in the deposited films. In addition, annealing of the material enabled the full tunability of its residual stress from the compressive to the tensile range. Infrared spectroscopy indicated that desorption of incorporated hydrogen was responsible for those changes. Assaying of resonant cantilevers fabricated from 200-nm-thick films yielded root-modulus-over-density values as high as √(E∕ρ)=8.35×103m∕s, comparable to those of silicon. Doubly clamped beams were also fabricated from 50-nm-thick films of low (σ=80MPa) and high (σ=220MPa) tensile stresses. Beam resonators fabricated in...

[1]  N. D. Rooij,et al.  Very high Q-factor resonators in monocrystalline silicon , 1990 .

[2]  C. W. Pearce,et al.  Characteristics of silicon nitride deposited by plasma‐enhanced chemical vapor deposition using a dual frequency radio‐frequency source , 1992 .

[3]  Wolfgang Kronast,et al.  LPCVD against PECVD for micromechanical applications , 1996 .

[4]  Polycrystalline silicon-carbide surface-micromachined vertical resonators-part I: growth study and device fabrication , 2005, Journal of Microelectromechanical Systems.

[5]  H. Craighead,et al.  Mechanical resonant immunospecific biological detector , 2000 .

[6]  Jeevak M. Parpia,et al.  Nanomechanical resonant structures in silicon nitride: fabrication, operation and dissipation issues , 2002 .

[7]  Carles Cané,et al.  Measurement of residual stress by slot milling with focused ion-beam equipment , 2006 .

[8]  B. D. Pant,et al.  Etching of Silicon Nitride in CCl2F2, CHF3, SiF4, and SF6 Reactive Plasma: A Comparative Study , 1999 .

[9]  A. Sarkissian,et al.  Low temperature study of loss mechanisms of mechanical oscillators , 2002 .

[10]  Harold G. Craighead,et al.  Measurement of nanomechanical resonant structures in single-crystal silicon , 1998 .

[11]  M. Roukes,et al.  VHF, UHF and microwave frequency nanomechanical resonators , 2005 .

[12]  Harold G. Craighead,et al.  Virus detection using nanoelectromechanical devices , 2004 .

[13]  Yu Wang,et al.  Surface chemical control of mechanical energy losses in micromachined silicon structures , 2003 .

[14]  Deepak Uttamchandani,et al.  Measurement of Young's modulus and internal stress in silicon microresonators using a resonant frequency technique , 1990 .

[15]  A comparative study of plasma enhanced chemically vapor deposited SiOH and SiNCH films using the environmentally benign precursor diethylsilane , 2002 .

[16]  I. Tittonen,et al.  Non-tilting out-of-plane mode high-Q mechanical silicon oscillator , 2005 .