Dissolution Behavior of Silicon Nitride Thin Films in a Simulated Ocular Environment

Author(s):  
Christoph Schade ◽  
Alex Phan ◽  
Kevin Joslin ◽  
Phuong Truong ◽  
Frank Talke

Abstract The time dependent dissolution of silicon nitride is studied in a simulated eye environment (controlled saline solution) as a function of temperature and pressure. Silicon nitride films manufactured by plasma-enhanced chemical vapor deposition (PECVD) and low-pressure chemical vapor deposition (LPCVD), respectively, were tested. The results revealed that both film types showed evidence of dissolution i.e., the films dissolved in the saline solution over time. At 37°C, PECVD and LPCVD silicon nitride membranes dissolved at a rate of 1.3 nm/day and 0.3 nm/day, respectively. It was found that at 23°C, the dissolution rate of the PECVD samples reduced to just 0.2 nm/day. Dissolution was not observed in samples tested in deionized water at 37°C. Titanium oxide layers (TiO2) were tested as protective layers to stop the dissolution. The results are important for implantable MEMS devices where silicon nitride is used as a functional membrane or as a protective layer.

2019 ◽  
Vol 681 ◽  
pp. 47-57 ◽  
Author(s):  
B. Cossou ◽  
S. Jacques ◽  
G. Couégnat ◽  
S.W. King ◽  
L. Li ◽  
...  

2016 ◽  
Vol 119 (14) ◽  
pp. 145702 ◽  
Author(s):  
Pramod Reddy ◽  
Shun Washiyama ◽  
Felix Kaess ◽  
M. Hayden Breckenridge ◽  
Luis H. Hernandez-Balderrama ◽  
...  

1992 ◽  
Vol 259 ◽  
Author(s):  
Mansour Moinpour ◽  
K. Bohannan ◽  
M. Shenasa ◽  
A. Sharif ◽  
G. Guzzo ◽  
...  

ABSTRACTA contamination control study of a Silicon Valley Group Thermco Systems Vertical Thermal Reactor(VTR) is presented. Trace elements of contaminants such as water vapor and oxygen have been shown to significantly affect the integrity of the silicon nitride film deposited by the low pressure chemical vapor deposition (LPCVD) process. This study documented the effects of process parameters on gaseous contamination levels, i.e., O2 and H2O vapor. Starting with a baseline process, the effects of an excursion of pre-deposition temperature ramp-up and stabilization condition, wafer load/unload and various post deposition conditions were explored. An axial profile of moisture and oxygen levels along the wafer load was obtained using Linde's Low Pressure Reactor Analysis(LPRAS) methodology. In addition, other process parameters such as gas flow rates during load and unload of wafers, pre-deposition N2 purge and process tube exposure time to ambient environment were- investigated. The wafers were analyzed for contaminants on the wafer surface or in the deposited silicon nitride film using FTIR and Auger spectroscopy techniques. They showed low levels of Si-O and no measurable Si-H or N-H bonds.


1996 ◽  
Vol 11 (6) ◽  
pp. 1483-1488 ◽  
Author(s):  
R. A. Levy ◽  
X. Lin ◽  
J. M. Grow ◽  
H. J. Boeglin ◽  
R. Shalvoy

This study investigates the use of the environmentally benign precursor tri(dimethylamino)silane (TDMAS) with NH3 to synthesize silicon nitride films by low pressure chemical vapor deposition. The growth kinetics are investigated as a function of deposition temperature, total pressure, and NH3/TDMAS flow ratios. The deposits are found to be essentially stoichiometric and to contain ∼5 at. % carbon when appropriate NH3 concentrations are present. The films are found in all cases to be amorphous and highly tensile. For optimized processing conditions, values of the refractive index are close to those reported for Si3N4. The film density is observed to increase with higher deposition temperatures up to 800 °C and then decrease due to the onset of gas phase nucleation effects. This behavior is readily reflected in the etch rate of those films. FTIR spectra reveal the presence of hydrogen even at high deposition temperatures (900 °C). Hardness and Young's modulus of the films are seen to increase with higher deposition temperatures, reaching saturation values near 20 and 185 GPa, respectively, above 800 °C.


2001 ◽  
Vol 40 (Part 1, No. 1) ◽  
pp. 7-11 ◽  
Author(s):  
Jean Luc Fay ◽  
Jean Beluch ◽  
Bernard Despax ◽  
Gérard Sarrabayrouse

1997 ◽  
Vol 495 ◽  
Author(s):  
Xian Lin ◽  
Denis Endisch ◽  
Xiaomeng Chen ◽  
Alain Kaloyeros

ABSTRACTFilms of silicon nitride are widely used in semiconductor technologies for very large scale integration (VLSI), thin film transistor (TFT), and solar cell applications. Current production technologies for silicon nitride use low pressure chemical vapor deposition (LPCVD) at temperatures > 700 °C or plasma enhanced chemical vapor deposition (PECVD) at temperatures below 450 °C. In this report, successful deposition of silicon nitride films by the low temperature thermal atmospheric pressure chemical vapor deposition (APCVD) method is described. Using a novel precursor tetraiodosilane (SiI4), deposition of silicon nitride has been achieved at temperature as low as 400 °C. Data pertaining to the dependence of film properties on deposition temperature are presented, along with a evaluation of the deposition rate, composition, chemical structure, and conformality of the resulting films.


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