Piezoresistive Properties of Boron-Doped PECVD Microcrystalline Silicon Films

1987 ◽  
Vol 106 ◽  
Author(s):  
Shu Wen Guo ◽  
Song Sheng Tan ◽  
Wei Yuan Wang
Keyword(s):  
Thermionic Emission ◽  
State Density ◽  
Gauge Factor ◽  
Optimized Design ◽  
Microcrystalline Silicon ◽  
Boron Doped ◽  
Hole Band ◽  
Si Films ◽  
P Type ◽  
Quartz Substrates

ABSTRACTThe piezoresistive properties of boron-doped PECVD microcrystalline Si films (μc-Si) deposited on SiO2 coated Si, covar or quartz substrates have been investigated. The relations between the gauge factor (G.F.) and doping concentrations as well as the film thickness etc. have been obtained experimentally. The maximum longitudinal G.F. of 25 and 20 are measured for Si and covar substrates respectively. An expression for calculating G.F. of P-type μc-Si is derived theoretically by use of the splitting model of heavy and light hole band at k=0 and the thermionic emission theory. The calculated dependences of G.F. on the doping concentrations, grain size and trap state density agree well with the experimental results, which offer a better understanding of the piezoresistive characteristics of μc-Si or poly-Si, and enable optimized design and fabrication of μc-Si or poly-Si strain gauges.

DEVELOPMENT OF HIGHLY CONDUCTIVE BORON-DOPED MICROCRYSTALLINE SILICON FILMS FOR APPLICATION IN SOLAR CELLS

2006 ◽  
Vol 20 (03) ◽  
pp. 303-314 ◽  
Author(s):  
QING-SONG LEI ◽  
ZHI-MENG WU ◽  
JIAN-PING XI ◽  
XIN-HUA GENG ◽  
YING ZHAO ◽  
...  
Keyword(s):  
Solar Cells ◽  
Substrate Temperature ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Silicon Films ◽  
Microcrystalline Silicon ◽  
Very High Frequency ◽  
Boron Doped ◽  
Deposition Processes ◽  
P Type

We have examined the deposition of highly conductive boron-doped microcrystalline silicon (μc- Si:H ) films for application in solar cells. Depositions were conducted in a very high frequency plasma enhanced chemical vapor deposition (VHF PECVD) chamber. In the deposition processes, various substrate temperatures (TS) were applied. Highly conductive p-type microcrystalline silicon films were obtained at substrate temperature lower than 210°C. The factors that affect the conductivity of the films were investigated. Results suggest that the dark conductivity, which was determined by the Hall mobility and carrier concentration, is influenced by the structure. The properties of the films are strongly dependent on the substrate temperature. With TS increasing, the dark conductivity (σd) increases initially; reach the maximum values at certain TS and then decrease. Also, we applied the boron-doped μc- Si:H as p-layers to the solar cells. An efficiency of about 8.5% for a solar cell with μc- Si:H p-layer was obtained.

Increase of temperature and crystallinity during electrical switching in microcrystalline silicon

2004 ◽  
Vol 808 ◽  
Author(s):  
Jian Hu ◽  
Paul Stradins ◽  
Howard M. Branz ◽  
Qi Wang ◽  
J.R. Weinberg-Wolf ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Microcrystalline Silicon ◽  
Electrical Measurements ◽  
Current Ramp ◽  
Device Resistance ◽  
Boron Doped ◽  
Current Stressing ◽  
Surface Reflectivity ◽  
Si Films ◽  
A Current

ABSTRACTWe investigate electrical stressing and switching in hydrogenated microcrystalline silicon (mc-Si:H) by thermal, and optical and electrical measurements of Cr/mc-Si:H/metal thin-film structures. Boron-doped microcrystalline Si films of 30-50 nm thick are deposited by hot-wire chemical vapor deposition (HWCVD) on Cr-coated glass at 160°C and contacted with Ag or Al. Switching in devices of size 5 to 30 mm is stimulated by a current-ramp from 10 nA to 50 mA. We find that the voltage across the mc-Si:H devices initially increases logarithmically with current, then saturates at 2∼3 V, and finally drops to a low value of 1 to 1.5 V. This drop indicates a permanent decrease of device resistance to below 1 kW. During current stressing, the surface temperature increases with the bias current, and the surface reflectivity changes. After switching, a small increase in crystalline fraction can be observed by micro-Raman scattering measurements. The observations suggest electrothermal processes which cause changes in microstructure of the mc-Si bulk during current stress.

Boron Doping Effects in Microcrystalline Silicon

2007 ◽  
Vol 989 ◽  
Author(s):  
Wolfhard Beyer ◽  
Lars Niessen ◽  
Frank Pennartz
Keyword(s):  
Doping Level ◽  
Amorphous Material ◽  
Boron Doping ◽  
Crystalline Material ◽  
Microcrystalline Silicon ◽  
High Concentration ◽  
Compact Structure ◽  
Boron Doped ◽  
Doping Effects ◽  
Si Films

AbstractConditions leading to high conductivities (up to 300 S/cm) in chlorosilane-based boron-doped microcrystalline Si:Cl:H films are investigated. It is found that the high conductivity originates primarily from the growth of highly crystalline material with a high concentration of boron. Furthermore, these films grow with relatively low chlorine and hydrogen concentrations of a few percent and, according to effusion measurements of hydrogen and implanted helium, in a relatively compact structure. At a boron doping level of 1%, admixture of 10% silane to the tetrachlorosilane results in the growth of amorphous material of low conductivity while for admixture of up to 90% of silicontetrafluoride, microcrystalline Si films with high conductivities can be grown.

Impact of doped microcrystalline silicon oxide layers on crystalline silicon surface passivation

2014 ◽  
Vol 92 (7/8) ◽  
pp. 758-762 ◽  
Author(s):  
K. Ding ◽  
U. Aeberhard ◽  
A. Lambertz ◽  
V. Smirnov ◽  
B. Holländer ◽  
...  
Keyword(s):  
Surface Passivation ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Microcrystalline Silicon ◽  
Float Zone ◽  
Boron Doped ◽  
The Poor ◽  
P Type ◽  
The Impact ◽  
Silicon Surface Passivation

This paper reports on a comparative study of the impact of phosphorous and boron doped microcrystalline silicon oxide (μc-SiOx:H) layers on the surface passivation of n- and p-type doped crystalline silicon float zone wafers in correlation with the material properties of the μc-SiOx:H layers. The poor surface passivation of μc-SiOx:H films deposited directly on c-Si surface might be attributed to the incorporation of doping impurities, the surface damaging by ion bombardment and (or) the low amount of hydrogen at the μc-SiOx:H/c-Si interface. The different impact of n- and p-type doped μc-SiOx:H films on the passivation of n- and p-type doped wafers with and without an additional a-SiOx:H passivation layer are correlated to the differences in the strength of the field effect at the heterojunction and to the presence of boron atoms that can cause the rupture of Si–H bonds.

Piezoresistive Sensors on Plastic Substrates Using Doped Microcrystalline Silicon

2001 ◽  
Vol 664 ◽  
Author(s):  
P. Alpuim ◽  
V. Chu ◽  
J. P. Conde
Keyword(s):  
Chemical Vapor ◽  
Repeated Measurements ◽  
Plastic Substrate ◽  
Gauge Factor ◽  
Radio Frequency Plasma ◽  
Microcrystalline Silicon ◽  
Plastic Substrates ◽  
Piezoresistive Sensors ◽  
Frequency Plasma ◽  
P Type

ABSTRACTThe piezoresistive behavior of optimized n-type and p-type microcrystalline silicon films deposited on polyethylene terephthalate plastic substrate by hot-wire and radio-frequency plasma-enhanced chemical vapor deposition, at a substrate temperature of 100 °C, is studied. A 4-point bending jig allowed the application of positive and negative strains in the films. Repeated measurements of the relative changes in the resistance of the samples during the strained condition showed reversible behavior, with p-type microcrystalline films having positive gauge factor in the range from 25 to 30 and n-type [.proportional]c-Si:H films having negative values of gauge factor from -40 to -10. The induced strain in the films was in the range between 0 and ±0.3%. A sensor utilizing the piezoresistive property of doped [.proportional]c-Si:H was used to map a contour with the shape of an Archimedes' spiral.

Highly Conductive p-type Microcrystalline Silicon Thin Films

1996 ◽  
Vol 420 ◽  
Author(s):  
M. Heintze ◽  
M. Schmitt
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Plasma Deposition ◽  
Growth Surface ◽  
Microcrystalline Silicon ◽  
Silicon Thin Films ◽  
Positive Ions ◽  
Boron Doped ◽  
P Type

AbstractThe plasma deposition of boron doped microcrystalline films was optimized with respect to crystallinity and doping efficiency. High room temperature conductivities up to 39 Scm−1 were achieved under condition when the energy of positive ions impinging on the growth surface is minimized.

scholarly journals Atomic Layer Deposition Grown Zinc-Oxide Based MIS-Type Schottky Barrier Diode

2018 ◽  
Author(s):  
Nuriye Kaymak ◽  
Esra Efil ◽  
Elanur Seven ◽  
Adem Tataroğlu ◽  
Sema Bilge Ocak ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Atomic Layer Deposition ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Thermionic Emission ◽  
Atomic Layer ◽  
Interface State ◽  
State Density ◽  
Layer Deposition ◽  
P Type

We report on the fabrication and electrical characteristics of zinc-oxide (ZnO) based metal-insulator-semiconductor (MIS) type Schottky barrier diodes (SBHs). ZnO thin layer on the p-type silicon substrate was fabricated by atomic layer deposition (ALD). The structure and surface properties of the thin film were characterized by X-ray diffraction (XRD), atomic force microscope (AFM) and secondary ion mass spectrometer (SIMS). The current-voltage (I-V) characteristics of Al/ALD-grown ZnO/p-Si diodes were measured under dark at room temperature. The electrical parameters such as ideality factor (n), series resistance (Rs) and barrier height (ϕb) of the diodes were analyzed using standard thermionic emission (TE) theory, Norde and Cheung method. The barrier height value obtained from I-V and Cheung method was found to be 0.73 eV and 0.76 eV, respectively. The interface state density (Dit) of the diodes was determined from the I-V characteristics. The nonideal behavior of measured parameters suggested the presence of interface states. The obtained results showed that the prepared diode can be used for NIR Schottky photodetector applications.

Sign in / Sign up

Export Citation Format

Share Document