Single Crystalline 4H-SiC MEMS Devices with N-P-N Epitaxial Structure

2014 ◽  
Vol 1693 ◽  
Author(s):  
Feng Zhao ◽  
Allen Lim ◽  
Zhibang Chen ◽  
Chih-Fang Huang

ABSTRACTIn this paper, single crystal 4H-SiC MEMS devices with n-p-n epitaxial structure was fabricated. A dopant-selective photoelectrochemical etching technique was applied to etch the sacrificial p-type SiC layer to release n-type SiC suspended structures on n-type SiC substrate. The selective etching was achieved by applying a bias which employs the different flat-band potentials of n-SiC and p-SiC in KOH solution. Such MEMS devices have the potential to fully exploit the superior properties of single crystal SiC for harsh environment operation, as well as mature epitaxial growth and device fabrication of 4H-SiC. The n-p-n structure, together with the previously reported p-n structure, extends the capability of monolithic integration between MEMS with electronic devices and circuits on SiC platform.

1992 ◽  
Vol 276 ◽  
Author(s):  
Mitsuteru Kimura ◽  
Kazuhiro Komatsuzaki

ABSTRACTMicroheater made of heavily Boron doped single crystal Si beam covered with SiO2 film, 1000×300×3 μm, is fabricated on the n type Si substrate by the anisotropic etching technique. As this microheater has an air bridge structure of low resistivity semiconductor material with positive but small temperature coefficient of resistance, a broad heating area up to 800 °C is easily obtained and it has quick response with the thermal time constant t of about 4 ms and has small power consumption. Since this heating area is made of p type layer in the n type substrate,this area can be electrically isolated from the substrate because of the formation of p-n junction.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Hyun Jung Kim ◽  
Yeonjoon Park ◽  
Hyung Bin Bae ◽  
Sang H. Choi

High-quality strain-relaxed SiGe films with a low twin defect density, high electron mobility, and smooth surface are critical for device fabrication to achieve designed performance. The mobilities of SiGe can be a few times higher than those of silicon due to the content of high carrier mobilities of germanium (p-type Si: 430 cm2/V·s, p-type Ge: 2200 cm2/V·s, n-type Si: 1300 cm2/V·s, and n-type Ge: 3000 cm2/V·s at 1016per cm3doping density). Therefore, radio frequency devices which are made with rhombohedral SiGe onc-plane sapphire can potentially run a few times faster than RF devices on SOS wafers. NASA Langley has successfully grown highly ordered single crystal rhombohedral epitaxy using an atomic alignment of the[111]direction of cubic SiGe on top of the[0001]direction of the sapphire basal plane. Several samples of rhombohedrally grown SiGe onc-plane sapphire show high percentage of a single crystalline over 95% to 99.5%. The electron mobilities of the tested samples are between those of single crystals Si and Ge. The measured electron mobility of 95% single crystal SiGe was 1538 cm2/V·s which is between 350 cm2/V·s (Si) and 1550 cm2/V·s (Ge) at 6 × 1017/cm3doping concentration.


2009 ◽  
Vol 615-617 ◽  
pp. 625-628 ◽  
Author(s):  
Anne Henry ◽  
Erik Janzén ◽  
Enrico Mastropaolo ◽  
Rebecca Cheung

Cantilever resonators have been fabricated from two types of materials, single crystal and polycrystalline 3C-SiC films. The films have been grown in a hot-wall chemical vapor deposition reactor on 100 mm diameter p-type boron-doped (100) Si wafer without rotation of the wafer. The crystal structure of the films have been accessed with X-ray diffraction. The cantilever devices have been fabricated using a one-step etch and release process; the beam length has been varied between 50 and 200 µm. Resonant frequencies in the range 110 KHz – 1.5 MHz and 50 – 750 KHz have been obtained for single crystal and polycrystalline SiC devices, respectively. Furthermore, the experimental resonance frequencies have been used to calculate the Young’s Modulus E for the two different types of SiC. The single crystal SiC, possessing a very high Young’s Modulus (446 GPa), should be an optimal material for RF-MEMS applications.


2004 ◽  
Vol 815 ◽  
Author(s):  
Maxime J. F. Guinel ◽  
Diego Rodriguez-Marek ◽  
M. Grant Norton ◽  
Robert B. Davis ◽  
David F. Bahr

AbstractElectronic devices based on single crystal SiC represent a good choice for a variety of new high temperature, high power electronics applications. The challenge is to develop a package that is resistant to thermal degradation in harsh environments. Conditions are extreme and this all but rules out only a handful of materials and materials systems. Polycrystalline SiC is the material that we have chosen to study as a suitable package and materials suitability/compatibility has been considered on several levels.


2012 ◽  
Vol 717-720 ◽  
pp. 529-532 ◽  
Author(s):  
Mohammad M. Islam ◽  
Chih Fang Huang ◽  
Feng Zhao

In this paper, we report single-crystal 4H-SiC resonant structures fabricated by dopant-selective photoelectrochemical etching. The frequency response of the resonant beams was characterized by a dynamic scanning method using AFM with the beams excited by a piezoelectric actuator under atmosphere pressure and room temperature. The beam with a length of 35 μm shows mechanical resonance at 945 kHz. The Young’s modulus of single-crystal SiC was derived from the measured resonant frequency. Single-crystal 4H-SiC resonators developed in this study fully exploit the excellent electrical, mechanical, and chemical properties of SiC, while dopant-selective photoelectrochemical etching technique significantly simplifies the fabrication process.


Author(s):  
N. Lewis ◽  
E. L. Hall ◽  
A. Mogro-Campero ◽  
R. P. Love

The formation of buried oxide structures in single crystal silicon by high-dose oxygen ion implantation has received considerable attention recently for applications in advanced electronic device fabrication. This process is performed in a vacuum, and under the proper implantation conditions results in a silicon-on-insulator (SOI) structure with a top single crystal silicon layer on an amorphous silicon dioxide layer. The top Si layer has the same orientation as the silicon substrate. The quality of the outermost portion of the Si top layer is important in device fabrication since it either can be used directly to build devices, or epitaxial Si may be grown on this layer. Therefore, careful characterization of the results of the ion implantation process is essential.


2007 ◽  
Vol 124-126 ◽  
pp. 1309-1312
Author(s):  
Nguyen Duc Hoa ◽  
Nguyen Van Quy ◽  
Gyu Seok Choi ◽  
You Suk Cho ◽  
Se Young Jeong ◽  
...  

A new type of gas sensor was realized by directly depositing carbon nanotube on nano channels of the anodic alumina oxide (AAO) fabricated on p-type silicon substrate. The carbon nanotubes were synthesized by thermal chemical vapor deposition at a very high temperature of 1200 oC to improve the crystallinity. The device fabrication process was also developed. The contact of carbon nanotubes and p-type Si substrate showed a Schottky behavior, and the Schottky barrier height increased with exposure to gases while the overall conductivity decreased. The sensors showed fast response and recovery to ammonia gas upon the filling (400 mTorr) and evacuation.


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