Charge and Current Transient Measurements on N-Type Hydrogenated Amorphous Silicon in the Relaxation Regime

1994 ◽  
Vol 336 ◽  
Author(s):  
Uwe W. Paschen ◽  
Daewon Kwon ◽  
J. David Cohen
Keyword(s):  
Thermal Emission ◽  
Depletion Region ◽  
Current Transient ◽  
Relaxation Model ◽  
Si Substrate ◽  
Capacitance Measurements ◽  
Transient Data ◽  
P Type ◽  
Hydrogenated Amorphous ◽  
Transient Measurements

ABSTRACTJunction capacitance measurements were employed to study the thermal emission of electrons after application of a voltage filling pulse on a 80 Vppm PH3 doped a-Si:H sample on p+ c-Si substrate. We show that these data can be explained in terms of the relaxation Model. In addition, the time dependence of the charge flow into the depletion region during the filling pulse is investigated by current transient Measurements. Finally, we present charge transient data for a 9 Vppm a-Si:H sample on n+ c-Si substrate and compare the results to those obtained on samples on p-type substrates.

Deep Defect Relaxation in Hydrogenated Amorphous Silicon: New Experimental Evidence and Implications

1998 ◽  
Vol 507 ◽  
Author(s):  
J. David Cohen ◽  
Fan Zhong ◽  
Daewon Kwon ◽  
C.-C. Chen
Keyword(s):  
Fermi Level ◽  
Emission Rate ◽  
Thermal Emission ◽  
Hydrogenated Amorphous Silicon ◽  
Depletion Region ◽  
Time Resolved ◽  
Apparent Shift ◽  
Hydrogenated Amorphous ◽  
Defect Relaxation ◽  
Thermal Emission Rate

ABSTRACTWe review modulated photocurrent experiments which indicate that thermal emission rate for Do defects in intrinsic samples varies in response to changes in the Fermi-level or quasi-Fermi position. This apparent shift in energy threshold is confirmed using time resolved sub-band-gap spectroscopy. We also demonstrate that such a variation of emission rate with changes in the Fermi-level position, if present within the depletion region near a barrier junction, is consistent with the details of the temperature dependence of the junction capacitance in intrinsic samples.

Density of States Spectroscopy in p-Type a-Si:H and a-SiC:H

1991 ◽  
Vol 219 ◽  
Author(s):  
Richard S. Crandall ◽  
Stanley J. Salamon ◽  
Yueqin Xu
Keyword(s):  
Density Of States ◽  
Hydrogenated Amorphous Silicon ◽  
Closed Form Expression ◽  
Form Expression ◽  
Junction Capacitance ◽  
Capacitance Measurements ◽  
Boron Doped ◽  
Exponential Increase ◽  
P Type ◽  
Hydrogenated Amorphous

ABSTRACTWe derive a closed form expression for differential junction capacitance applicable when the density of states (DOS) varies exponentially with energy. Using this expression, we analyze p/n junction capacitance measurements that probe the DOS in boron doped hydrogenated amorphous silicon and silicon carbide alloy. In both materials we find that the p-layer DOS is described by an exponential increase with energy above the Fermi level.

Exploration of Defect Relaxation Dynamics in Hydrogenated Amorphous Silicon using Temperature Switching Experiments

1994 ◽  
Vol 336 ◽  
Author(s):  
Adam Gardner ◽  
J. David Cohen
Keyword(s):  
Density Of States ◽  
Thermal Emission ◽  
Hydrogenated Amorphous Silicon ◽  
Relaxation Processes ◽  
Relaxation Dynamics ◽  
Temperature Step ◽  
Thermally Activated ◽  
Hydrogenated Amorphous ◽  
Defect Relaxation ◽  
Transient Measurements

ABSTRACTWe have carried out a series of charge transient measurements on a-Si:H in which we insert a double temperature step during the period when electrons are being emitted from deep defects. The behavior of this emitted defect charge is completely inconsistent with any density of states that remains static during the emission; that is, defect relaxation must be invoked. Such measurements allow us to separate the temperature dependence of relaxation from that of thermal emission. In particular, we demonstrate that the emission itself exhibits thermally activated behavior in spite of the ongoing relaxation processes.

scholarly journals Impact of Silicon Substrate with Low Resistivity on Vertical Leakage Current in AlGaN/GaN HEMTs

2019 ◽  
Vol 9 (11) ◽  
pp. 2373 ◽  
Author(s):  
Chunyan Song ◽  
Xuelin Yang ◽  
Panfeng Ji ◽  
Jun Tang ◽  
Shan Wu ◽  
...  
Keyword(s):  
Leakage Current ◽  
Impact Ionization ◽  
Electron Injection ◽  
Depletion Region ◽  
High Electron ◽  
Si Substrate ◽  
Low Resistivity ◽  
Si Substrates ◽  
Vertical Leakage ◽  
P Type

The role of low-resistivity substrate on vertical leakage current (VLC) of AlGaN/GaN-on-Si epitaxial layers has been investigated. AlGaN/GaN high-electron-mobility transistors (HEMTs) grown on both p-type and n-type Si substrates with low resistivity are applied to analyze the vertical leakage mechanisms. The activation energy (Ea) for p-type case is higher than that for n-type at 0–600 V obtained by temperature-dependent current-voltage measurements. An additional depletion region in the region of 0–400 V forms at the AlN/p-Si interface but not for AlN/n-Si. That depletion region leads to a decrease of electron injection and hence effectively reduces the VLC. While in the region of 400–600 V, the electron injection from p-Si substrate increases quickly compared to n-Si substrate, due to the occurrence of impact ionization in the p-Si substrate depletion region. The comparative results indicate that the doping type of low-resistivity substrate plays a key role for VLC.

Electrical properties of boron doped CVD diamond after plasma cleaning probed by capacitance-voltage profiling

2014 ◽  
Vol 1634 ◽  
Author(s):  
Luana S. Araujo ◽  
Olivia Berengue ◽  
Maurício Baldan ◽  
Neidenei Ferreira ◽  
João Moro ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Chemical Vapor ◽  
Diamond Surface ◽  
Plasma Cleaning ◽  
Electrical Characteristics ◽  
Capacitance Measurements ◽  
Boron Doped ◽  
Capacitance Voltage ◽  
Surface Adsorbates ◽  
P Type

ABSTRACTDoped diamond films grown by chemical vapor techniques has been used to study hydrogen and oxygen terminated diamond. It is known that the electrical characteristics of metal-diamond interface are strongly affected by the diamond surface features. O2 plasma treatment was used as a cleaning procedure for as grown diamond samples leading to changes in the capacitance measurements after treatment. The alteration in the characteristics of the samples can be attributed to the surface adsorbates like hydrogen and water vapor present in the atmosphere. The results indicates that the O2 plasma treatment was effective in cleaning the surface revealing the expected features of a p-type diamond film.

1/f Noise in Mott Variable Range Hopping Conduction in p-type Amorphous Silicon

2015 ◽  
Vol 1770 ◽  
pp. 25-30 ◽  
Author(s):  
V.C. Lopes ◽  
A.J. Syllaios ◽  
D. Whitfield ◽  
K. Shrestha ◽  
C.L. Littler
Keyword(s):  
Electrical Conductivity ◽  
Amorphous Silicon ◽  
Chemical Vapor ◽  
Variable Range Hopping ◽  
Temperature Dependent ◽  
Noise Component ◽  
Variable Range ◽  
Noise Measurements ◽  
P Type ◽  
Hydrogenated Amorphous

ABSTRACTWe report on electrical conductivity and noise measurements made on p-type hydrogenated amorphous silicon (a-Si:H) thin films prepared by Plasma Enhanced Chemical Vapor Deposition (PECVD). The temperature dependent electrical conductivity can be described by the Mott Variable Range Hopping mechanism. The noise at temperatures lower than ∼ 400K is dominated by a 1/f component which follows the Hooge model and correlates with the Mott conductivity. At high temperatures there is an appreciable G-R noise component.

Raman Characterization of Protocrystalline Silicon Films

2009 ◽  
Vol 1153 ◽  
Author(s):  
A. J. Syllaios ◽  
S. K. Ajmera ◽  
G. S. Tyber ◽  
C. L. Littler ◽  
R. E. Hollingworth
Keyword(s):  
Substrate Temperature ◽  
Dopant Concentration ◽  
Hydrogen Dilution ◽  
Spectral Peaks ◽  
And Performance ◽  
And Shifts ◽  
P Type ◽  
Hydrogenated Amorphous ◽  
Raman Spectral

AbstractAn increasingly important application of thin film hydrogenated amorphous silicon (α-Si:H) is in infrared detection for microbolometer thermal imaging arrays. Such arrays consist of thin α-Si:H films that are integrated into a floating thermally isolated membrane structure. Among the α-Si:H material properties affecting the design and performance of microbolometers is the microstructure. In this work, Raman spectroscopy is used to study changes in the microstructure of protocrystalline p-type α-Si:H films grown by PECVD as substrate temperature, dopant concentration, and hydrogen dilution are varied. The films exhibit the four Raman spectral peaks corresponding to the TO, LO, LA, and TA modes. It is found that the TO Raman peak becomes increasingly well defined (decreasing line width and increasing intensity), and shifts towards the crystalline TO energy as substrate temperature is increased, H dilution of the reactants is increased, or as dopant concentration is decreased.

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