Oxidized Porous Silicon Moisture Sensors for Evaluation of Microelectronic Packaging

1991 ◽  
Vol 225 ◽  
Author(s):  
M. J. Kelly ◽  
T. R. Guilinger ◽  
D. W. Peterson ◽  
M. R. Tuck ◽  
J. N. Sweet
Keyword(s):  
Porous Silicon ◽  
Integrated Circuits ◽  
Sensing Element ◽  
Oxidation Treatment ◽  
Moisture Barrier ◽  
Barrier Coating ◽  
Oxidized Porous Silicon ◽  
Consistent Performance ◽  
Silicon Based ◽  
Intentional Introduction

ABSTRACTAccurate moisture measurements in microelectronic assemblies are crucial in assessing reliability of integrated circuits (ICs). We describe the fabrication and use of a silicon-based device for evaluation of moisture barrier coatings. The capacitive moisture sensors use oxidized porous silicon (OPS) as the sensing element. Porous silicon (PS) is formed by anodization of Si in hydrofluoric acid (HF). Oxidation of PS in oxygen produces OPS, which is also porous if an appropriate starting microstructure and oxidation treatment are selected. Metallization layers on the OPS and the wafer back complete the capacitor structure. The capacitance of OPS sensors is functionally related to the moisture content of the surrounding atmosphere. For example, the capacitance of one sensor changed from 4 nF/cm2when exposed to a moisture level of 300 ppm by volume (ppmv) to 36 nF/cm2at 10,000 ppmv. In addition to this excellent sensitivity, capacitor response to step changes in moisture is rapid and reversible. The sensors are also rugged, as demonstrated by their consistent performance during accelerated testing at 85% relative humidity and 140°C. A silicon nitride IC moisture barrier coating was deposited on sensors of this type after normal ceramic dual in-line packaging. Sensor operability after coating deposition was confirmed following intentional introduction of a pinhole into the moisture barrier coating.

scholarly journals Fabrication of Porous Silicon Based Humidity Sensing Elements on Paper

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Tero Jalkanen ◽  
Anni Määttänen ◽  
Ermei Mäkilä ◽  
Jaani Tuura ◽  
Martti Kaasalainen ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Smart Cities ◽  
Low Cost ◽  
Electrical Characterization ◽  
Fabrication Process ◽  
Sensing Element ◽  
Paper Substrate ◽  
Roll To Roll ◽  
Silver Electrodes ◽  
Silicon Based

A roll-to-roll compatible fabrication process of porous silicon (pSi) based sensing elements for a real-time humidity monitoring is described. The sensing elements, consisting of printed interdigitated silver electrodes and a spray-coated pSi layer, were fabricated on a coated paper substrate by a two-step process. Capacitive and resistive responses of the sensing elements were examined under different concentrations of humidity. More than a three orders of magnitude reproducible decrease in resistance was measured when the relative humidity (RH) was increased from 0% to 90%. A relatively fast recovery without the need of any refreshing methods was observed with a change in RH. Humidity background signal and hysteresis arising from the paper substrate were dependent on the thickness of sensing pSi layer. Hysteresis in most optimal sensing element setup (a thick pSi layer) was still noticeable but not detrimental for the sensing. In addition to electrical characterization of sensing elements, thermal degradation and moisture adsorption properties of the paper substrate were examined in connection to the fabrication process of the silver electrodes and the moisture sensitivity of the paper. The results pave the way towards the development of low-cost humidity sensors which could be utilized, for example, in smart packaging applications or in smart cities to monitor the environment.

scholarly journals Non-oxidized porous silicon-based power AC switch peripheries

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
Samuel Menard ◽  
Angélique Fèvre ◽  
Damien Valente ◽  
Jérôme Billoué ◽  
Gaël Gautier
Keyword(s):  
Porous Silicon ◽  
Oxidized Porous Silicon ◽  
Silicon Based

Oxidized Porous Silicon Based SOI: Untapped Resources

2002 ◽  
pp. 309-327
Author(s):  
V. Bondarenko ◽  
V. Yakovtseva ◽  
L. Dolgyi ◽  
N. Vorozov ◽  
S. Volchek ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Oxidized Porous Silicon ◽  
Silicon Based

TEM analysis of light emitting porous silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1398-1399
Author(s):  
M. W. Cole ◽  
J. F. Harvey ◽  
R.A. Lux ◽  
D.W. Eckart
Keyword(s):  
Porous Silicon ◽  
Integrated Circuits ◽  
Light Emission ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Light Emitting ◽  
Visible Luminescence ◽  
Transmission Electron ◽  
Potential Applications ◽  
Silicon Based

The recent observations of visible light emission from porous silicon layers (PSL) have attracted much interest due to its potential applications in silicon based optoelectronic integrated circuits, optical memories and advanced display systems. To realize these potential applications this material must be fully characterized. Specifically, the microstructure must be studied in order to understand the origin of the light emission. Unfortunately, the issue of the detailed geometry of porous silicon is not fully resolved because of the difficulty in performing transmission electron microscopy (TEM) measurements on these fragile structures. One of the first microstructural studies on visible emitting PSL, presented by Cullis and Canham, showed the material to be composed of needle-like structures having a cross sectional diameter of 3nm. It was suggested that the visible luminescence in this material is due to quantum confinement of these small structures. A major limitation of this work was the method of TEM sample preparation.

scholarly journals Anisotropic polarization memory in thermally oxidized porous silicon

2000 ◽  
Vol 77 (15) ◽  
pp. 2316-2318 ◽  
Author(s):  
Hideki Koyama ◽  
Philippe M. Fauchet
Keyword(s):  
Porous Silicon ◽  
Oxidized Porous Silicon

Optical gain in dye-doped polymer waveguides using oxidized porous silicon cladding

2007 ◽  
Author(s):  
Daniel Navarro-Urrios ◽  
Mher Ghulinyan ◽  
Paolo Bettotti ◽  
Néstor Capuj ◽  
Claudio J. Oton ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Optical Gain ◽  
Polymer Waveguides ◽  
Oxidized Porous Silicon ◽  
Doped Polymer

Observation of quantum-confined luminescence in partially oxidized porous silicon

2000 ◽  
Vol 80 (4) ◽  
pp. 679-689 ◽  
Author(s):  
Giampiero Amato ◽  
L. Boarino ◽  
D. Midellino ◽  
A. M. Rossi
Keyword(s):  
Porous Silicon ◽  
Oxidized Porous Silicon ◽  
Quantum Confined

Strongly Superlinear Light Emission and Large Induced Absorption in Oxidized Porous Silicon Films

1998 ◽  
Vol 536 ◽  
Author(s):  
H. Koyama ◽  
P. M. Fauchet
Keyword(s):  
Porous Silicon ◽  
Thermal Effects ◽  
Light Emission ◽  
Laser Intensity ◽  
Excitation Intensity ◽  
Silicon Films ◽  
Free Standing ◽  
Induced Absorption ◽  
Cw Laser ◽  
Oxidized Porous Silicon

AbstractThe optical properties of oxidized free-standing porous silicon films excited by a cw laser have been investigated. It is found that samples oxidized at 800–950 °C show a strongly superlinear light emission at an excitation intensity of ∼10 W/cm2. This emission has a peak at 900–1100 nm and shows a blueshift as the oxidation temperature is increased. These samples also show a very large induced absorption, where the transmittance is found to decrease reversibly by ≤99.7 %.The induced absorption increases linearly with increasing pump laser intensity. Both the superlinear emission and the large induced absorption are quenched when the samples are attached to materials with a higher thermal conductivity, suggesting that laser-induced thermal effects are responsible for these phenomena.

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