scholarly journals Demonstration of a Robust All-Silicon-Carbide Intracortical Neural Interface

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 412 ◽  
Author(s):  
Evans Bernardin ◽  
Christopher Frewin ◽  
Richard Everly ◽  
Jawad Ul Hassan ◽  
Stephen Saddow
Keyword(s):  
Silicon Carbide ◽  
High Performance ◽  
Electrical Characterization ◽  
Electrode Impedance ◽  
Voltage Range ◽  
Promising Solution ◽  
Multiple Materials ◽  
Diode Behavior ◽  
Materials Used ◽  
P Type

Intracortical neural interfaces (INI) have made impressive progress in recent years but still display questionable long-term reliability. Here, we report on the development and characterization of highly resilient monolithic silicon carbide (SiC) neural devices. SiC is a physically robust, biocompatible, and chemically inert semiconductor. The device support was micromachined from p-type SiC with conductors created from n-type SiC, simultaneously providing electrical isolation through the resulting p-n junction. Electrodes possessed geometric surface area (GSA) varying from 496 to 500 K μm2. Electrical characterization showed high-performance p-n diode behavior, with typical turn-on voltages of ~2.3 V and reverse bias leakage below 1 nArms. Current leakage between adjacent electrodes was ~7.5 nArms over a voltage range of −50 V to 50 V. The devices interacted electrochemically with a purely capacitive relationship at frequencies less than 10 kHz. Electrode impedance ranged from 675 ± 130 kΩ (GSA = 496 µm2) to 46.5 ± 4.80 kΩ (GSA = 500 K µm2). Since the all-SiC devices rely on the integration of only robust and highly compatible SiC material, they offer a promising solution to probe delamination and biological rejection associated with the use of multiple materials used in many current INI devices.

Incorporation and Diffusion of P-Type Dopants for Metal Organic Vapor Phase Epitaxy

1988 ◽  
Vol 144 ◽  
Author(s):  
M. A. Tischler ◽  
T. F. Kuech
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
High Performance ◽  
Electrical Characterization ◽  
Bipolar Transistors ◽  
Organic Vapor ◽  
Dopant Profile ◽  
Metal Organic ◽  
Initial Placement ◽  
P Type ◽  
And Diffusion

ABSTRACTThe control of p-type dopants is very important in producing high performance minority carrier devices such as heterojunction bipolar transistors (HBT) and lasers. In this study, an electrical characterization technique is described which is very sensitive to the p-type dopant profile in a heterojunction. Both the placement of the dopant, i.e. the as-grown profile, and thermal diffusion effects have been investigated. The factors which control the initial placement and subsequent diffusion of the dopant species have been determined and used to produce device-quality GaAs/Al0.30Ga0.70As p+/n heterojunctions.

Electrical Characterization and Reliability of Nitrided-Gate Insulators for N- and P-Type 4H-SiC MIS Devices

2010 ◽  
Vol 645-648 ◽  
pp. 825-828 ◽  
Author(s):  
Masato Noborio ◽  
Michael Grieb ◽  
Anton J. Bauer ◽  
Dethard Peters ◽  
Peter Friedrichs ◽  
...  
Keyword(s):  
High Performance ◽  
Electrical Characterization ◽  
Interface State ◽  
State Density ◽  
Channel Mobility ◽  
Gate Insulators ◽  
Interface Characteristics ◽  
Mis Devices ◽  
P Type ◽  
Mis Capacitors

In this paper, nitrided insulators such as N2O-grown oxides, deposited SiO2 annealed in N2O, and deposited SiNx/SiO2 annealed in N2O on thin-thermal oxides have been investigated for realization of high performance n- and p-type 4H-SiC MIS devices. The MIS capacitors were utilized to evaluate MIS interface characteristics and the insulator reliability. The channel mobility was determined by using the characteristics of planar MISFETs. Although the N2O-grown oxides are superior to the dry O2-grown oxides, the deposited SiO2 and the deposited SiNx/SiO2 exhibited lower interface state density (n-MIS: below 7x1011 cm-2eV-1 at EC-0.2 eV, p-MIS: below 6x1011 cm-2eV-1 at EV+0.2 eV) and higher channel mobility (n-MIS: over 25 cm2/Vs, p-MIS: over 10 cm2/Vs). In terms of reliability, the deposited SiO2 annealed in N2O exhibits a high charge-to-breakdown over 50 C/cm2 at room temperature and 15 C/cm2 at 200°C. The nitrided-gate insulators formed by deposition method have superior characteristics than the thermal oxides grown in N2O.

scholarly journals Electrical Characterization of Nanopolyaniline/Porous Silicon Heterojunction at High Temperatures

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Salah E. El-Zohary ◽  
M. A. Shenashen ◽  
Nageh K. Allam ◽  
T. Okamoto ◽  
M. Haraguchi
Keyword(s):  
Electron Microscopy ◽  
Porous Silicon ◽  
Ideality Factor ◽  
Series Resistance ◽  
In Situ Polymerization ◽  
Electrical Characterization ◽  
Different Temperatures ◽  
Diode Behavior ◽  
Increasing Temperature ◽  
P Type

Nanopolyaniline/p-type porous silicon (NPANI/PSi) heterojunction films were chemically fabricated via in situ polymerization. The composition and morphology of the nanopolymer were confirmed using Fourier transform infrared, scanning electron microscopy, UV-visible, and transmission electron microscopy techniques. The results indicated that the polymerization took place throughout the porous layer. TheI-Vmeasurements, performed at different temperatures, enabled the calculation of ideality factor, barrier height, and series resistance of those films. The obtained ideality factor showed a nonideal diode behavior. The series resistance was found to decrease with increasing temperature.

scholarly journals Fabrication of a Monolithic Implantable Neural Interface from Cubic Silicon Carbide

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 430 ◽  
Author(s):  
Mohammad Beygi ◽  
John T. Bentley ◽  
Christopher L. Frewin ◽  
Cary A. Kuliasha ◽  
Arash Takshi ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Microelectrode Array ◽  
Electrochemical Impedance ◽  
Chemical Vapor ◽  
Silicon On Insulator ◽  
Free Standing ◽  
Multiple Materials ◽  
Materials Used ◽  
Cubic Silicon Carbide

One of the main issues with micron-sized intracortical neural interfaces (INIs) is their long-term reliability, with one major factor stemming from the material failure caused by the heterogeneous integration of multiple materials used to realize the implant. Single crystalline cubic silicon carbide (3C-SiC) is a semiconductor material that has been long recognized for its mechanical robustness and chemical inertness. It has the benefit of demonstrated biocompatibility, which makes it a promising candidate for chronically-stable, implantable INIs. Here, we report on the fabrication and initial electrochemical characterization of a nearly monolithic, Michigan-style 3C-SiC microelectrode array (MEA) probe. The probe consists of a single 5 mm-long shank with 16 electrode sites. An ~8 µm-thick p-type 3C-SiC epilayer was grown on a silicon-on-insulator (SOI) wafer, which was followed by a ~2 µm-thick epilayer of heavily n-type (n+) 3C-SiC in order to form conductive traces and the electrode sites. Diodes formed between the p and n+ layers provided substrate isolation between the channels. A thin layer of amorphous silicon carbide (a-SiC) was deposited via plasma-enhanced chemical vapor deposition (PECVD) to insulate the surface of the probe from the external environment. Forming the probes on a SOI wafer supported the ease of probe removal from the handle wafer by simple immersion in HF, thus aiding in the manufacturability of the probes. Free-standing probes and planar single-ended test microelectrodes were fabricated from the same 3C-SiC epiwafers. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed on test microelectrodes with an area of 491 µm2 in phosphate buffered saline (PBS) solution. The measurements showed an impedance magnitude of 165 kΩ ± 14.7 kΩ (mean ± standard deviation) at 1 kHz, anodic charge storage capacity (CSC) of 15.4 ± 1.46 mC/cm2, and a cathodic CSC of 15.2 ± 1.03 mC/cm2. Current-voltage tests were conducted to characterize the p-n diode, n-p-n junction isolation, and leakage currents. The turn-on voltage was determined to be on the order of ~1.4 V and the leakage current was less than 8 μArms. This all-SiC neural probe realizes nearly monolithic integration of device components to provide a likely neurocompatible INI that should mitigate long-term reliability issues associated with chronic implantation.

High performance 0.25 [micro sign]m p-type Ge/SiGe MODFETs

1998 ◽  
Vol 34 (19) ◽  
pp. 1888 ◽  
Author(s):  
G. Höck ◽  
T. Hackbarth ◽  
U. Erben ◽  
E. Kohn ◽  
U. König
Keyword(s):  
High Performance ◽  
P Type

P-type Co3O4 nanoarrays decorated on the surface of n-type flower-like WO3 nanosheets for high-performance gas sensing

2019 ◽  
Vol 288 ◽  
pp. 104-112 ◽  
Author(s):  
Yanghai Gui ◽  
Lele Yang ◽  
Kuan Tian ◽  
Hongzhong Zhang ◽  
Shaoming Fang
Keyword(s):  
High Performance ◽  
Gas Sensing ◽  
P Type ◽  
Co3o4 Nanoarrays

Thermodynamics and Microstructure Development in the Thin Film Reaction of Aluminum on Silicon Carbide

1995 ◽  
Vol 403 ◽  
Author(s):  
T. S. Hayes ◽  
F. T. Ray ◽  
K. P. Trumble ◽  
E. P. Kvam
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Silicon Carbide ◽  
Ohmic Contacts ◽  
Microstructure Development ◽  
P Type ◽  
Microstructural Studies

AbstractA refined thernodynamic analysis of the reaction between molen Al and SiC is presented. The calculations indicate much higher Si concentrations for saturation with respect to AkC 3 formation than previously reported. Preliminary microstructural studies confirm the formation of interfacial A14C3 for pure Al thin films on SiC reacted at 9000C. The implications of the calculations and experimental observations for the production of ohmic contacts to p-type SiC are discussed.

Sign in / Sign up

Export Citation Format

Share Document