TY - GEN
T1 - Characterization of flourocarbon SAM coated MEMS tribogauge
AU - Vijayasai, Ashwin
AU - Ramachandran, Gautham
AU - Sivakumar, Ganapathy
AU - Anderson, Charlie
AU - Gale, Richard
AU - Dallas, Tim
PY - 2012
Y1 - 2012
N2 - A MEMS tribogauge was used for on-chip and in-situ characterization of nano-tribological phenomena (stiction, friction, and wear of coated polysilicon surfaces). The device was fabricated using the SUMMiT-V process. Measurements were made on sidewall surfaces on the polysilicon-3 layer. The device consists of two orthogonally positioned comb-drive assemblies that are used for both actuation and sensing. One assembly is used to apply a normal load (F n) to contacting surface, while the other induces a tangential load (F T). Precise position control is tracked by employing a LabVIEW controlled AD7747 capacitance sense mechanism. The resolution of the characterization apparatus is ±10nm. Three MEMS tribogauge devices are tested; two of them have a chemisorbed layer of self-assembled monolayer (SAM) coatings and one with no SAM coating. The two types of SAM coatings are FOTS and 'Sandia vapor-SAM' (SVSAM). The tribogauge with no FSAM coating is either UV-Ozone or 'air plasma' treated to remove organic contaminants leaving behind -OH bonds on top of the MEMS surface (native oxide, SiO 2). Characterization using the tribogauge for each coating type includes: measurement of baseline stiction force (F FOTS baseline, F SVSAM baseline), static and dynamic coefficient of friction (F FOTS s,F FOTS d ), induced stiction force calculated after specific load cycles (F normal induced,F scrub inducd ). Experiments showed that the induced stiction force increases in proportion to the increase in the number of load cycles, indicating degradation of the FSAM coating and topographical changes to the interacting surfaces. The UV-Ozone /air plasma treated pristine tribogauge was used to measure the stiction force of the device with no SAM coating (F cleaned baseline).
AB - A MEMS tribogauge was used for on-chip and in-situ characterization of nano-tribological phenomena (stiction, friction, and wear of coated polysilicon surfaces). The device was fabricated using the SUMMiT-V process. Measurements were made on sidewall surfaces on the polysilicon-3 layer. The device consists of two orthogonally positioned comb-drive assemblies that are used for both actuation and sensing. One assembly is used to apply a normal load (F n) to contacting surface, while the other induces a tangential load (F T). Precise position control is tracked by employing a LabVIEW controlled AD7747 capacitance sense mechanism. The resolution of the characterization apparatus is ±10nm. Three MEMS tribogauge devices are tested; two of them have a chemisorbed layer of self-assembled monolayer (SAM) coatings and one with no SAM coating. The two types of SAM coatings are FOTS and 'Sandia vapor-SAM' (SVSAM). The tribogauge with no FSAM coating is either UV-Ozone or 'air plasma' treated to remove organic contaminants leaving behind -OH bonds on top of the MEMS surface (native oxide, SiO 2). Characterization using the tribogauge for each coating type includes: measurement of baseline stiction force (F FOTS baseline, F SVSAM baseline), static and dynamic coefficient of friction (F FOTS s,F FOTS d ), induced stiction force calculated after specific load cycles (F normal induced,F scrub inducd ). Experiments showed that the induced stiction force increases in proportion to the increase in the number of load cycles, indicating degradation of the FSAM coating and topographical changes to the interacting surfaces. The UV-Ozone /air plasma treated pristine tribogauge was used to measure the stiction force of the device with no SAM coating (F cleaned baseline).
UR - http://www.scopus.com/inward/record.url?scp=84858991581&partnerID=8YFLogxK
U2 - 10.1117/12.909301
DO - 10.1117/12.909301
M3 - Conference contribution
AN - SCOPUS:84858991581
SN - 9780819488930
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS and Nanodevices XI
Y2 - 23 January 2012 through 24 January 2012
ER -