Boron Doping in Si-MBE

1991 ◽  
Vol 220 ◽  
Author(s):  
K. Eberl ◽  
S. S. Iyer ◽  
S. L. Delage ◽  
B. A. Ek ◽  
J. M. Cotte
Keyword(s):  
Substrate Temperature ◽  
Boron Doping ◽  
Source Material ◽  
Memory Effects ◽  
Lower Growth ◽  
Gas Source ◽  
Elemental Boron ◽  
P Type ◽  
Incorporation Efficiency

ABSTRACTWe have investigated p-type doping of Si and SiGc layers in M BE by using two different boron sources. One is a SiB alloy which is prepared in situ by melting elemental boron into Si. Typical B concentrations in the source material are a few percent. Doping levels within 1×1018 cm−3 and 5.5×1019 cm−3 can be adjusted within the temperature range of 350°C to 850°C. No indication of segregation or memory effects is found. The activation is between 90 and 100%. The second p-type doping source investigated is a diborane (B2H6) gas source. Diborane provides doping capability in the range between 1016. to 1020. The incorporation efficiency at 550°C is about 2×10'3. It depends on the diborane exposure and the substrate temperature. The activation at 550°C is above 90%. For lower growth temperatures the activation is considerably reduced. The problem of memory effects is discussed.

HgCdTe MBE Technology : A Focus On Chemical Doping

1993 ◽  
Vol 302 ◽  
Author(s):  
Owen K. Wu
Keyword(s):  
Double Layer ◽  
Focal Plane ◽  
Memory Effects ◽  
Current Status ◽  
Chemical Doping ◽  
Mbe Growth ◽  
Heterojunction Structure ◽  
P Type ◽  
Growth Technology

ABSTRACTHgCdTe MBE technology is becoming a mature growth technology for infrared focal plane array applications. The ability to dope HgCdTe with In(n-type) and As(p-type) dopants in-situ provides greater flexibilities for fabricating heterojunction devices. In this paper, we will first discuss the current status of HgCdTe MBE growth and then focus on the key results in the control of In(n-type) doping, various approaches and breakthroughs in the growth of As(p-type) doped HgCdTe and issues related to doping such as memory effects and dopants activation. In addition, device results from double layer heterojunction structure(DLHJ) will be briefly discussed.

HgCdTe MBE Technology: A Focus on Chemical Doping

1994 ◽  
Vol 299 ◽  
Author(s):  
Owen K. Wu
Keyword(s):  
Double Layer ◽  
Focal Plane ◽  
Memory Effects ◽  
Current Status ◽  
Chemical Doping ◽  
Mbe Growth ◽  
Heterojunction Structure ◽  
P Type ◽  
Growth Technology

AbstractHgCdTe MBE technology is becoming a mature growth technology for infrared focal plane array applications. The ability to dope HgCdTe with In(n-type) and As(p-type) dopants in-situ provides greater flexibilities for fabricating heterojunction devices. In this paper, we will first discuss the current status of HgCdTe MBE growth and then focus on the key results in the control of In(n-type) doping, various approaches and breakthroughs in the growth of As(p-type) doped HgCdTe and issues related to doping such as memory effects and dopants activation. In addition, device results from double layer heterojunction structure(DLHJ) will be briefly discussed.

In Situ Boron and Aluminum Doping and Their Memory Effects in 4H-SiC Homoepitaxial Layers Grown by Hot-Wall LPCVD

2008 ◽  
Vol 600-603 ◽  
pp. 147-150 ◽  
Author(s):  
Guo Sheng Sun ◽  
Yong Mei Zhao ◽  
Liang Wang ◽  
Lei Wang ◽  
Wan Shun Zhao ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Voltage Drop ◽  
Hole Concentration ◽  
Hole Mobility ◽  
Memory Effects ◽  
Aluminum Concentration ◽  
Pin Diodes ◽  
P Type

The in-situ p-type doping of 4H-SiC grown on off-oriented (0001) 4H-SiC substrates was performed with trimethylaluminum (TMA) and/or diborane (B2H6) as the dopants. The incorporations of Al and B atoms and their memory effects and the electrical properties of p-type 4H-SiC epilayers were characterized by secondary ion mass spectroscopy (SIMS) and Hall effect measurements, respectively. Both Al- and B-doped 4H-SiC epilayers were p-type conduction. It was shown that the profiles of the incorporated boron and aluminum concentration were in agreement with the designed TMA and B2H6 flow rate diagrams. The maximum hole concentration for the Al doped 4H-SiC was 3.52×1020 cm-3 with Hall mobility of about 1 cm2/Vs and resistivity of 1.6~2.2×10-2 Wcm. The heavily boron-doped 4H-SiC samples were also obtained with B2H6 gas flow rate of 5 sccm, yielding values of 0.328 Wcm for resistivity, 5.3×1018 cm-3 for hole carrier concentration, and 7 cm2/Vs for hole mobility. The doping efficiency of Al in SiC is larger than that of B. The memory effects of Al and B were investigated in undoped 4H-SiC by using SIMS measurement after a few run of doped 4H-SiC growth. It was clearly shown that the memory effect of Al is stronger than that of B. It is suggested that p-type 4H-SiC growth should be carried out in a separate reactor, especially for Al doping, in order to avoid the join contamination on the subsequent n-type growth. 4H-SiC PiN diodes were fabricated by using heavily B doped epilayers. Preliminary results of PiN diodes with blocking voltage of 300 V and forward voltage drop of 3.0 V were obtained.

Epitaxial Ge Films on Si Substrates

1987 ◽  
Vol 91 ◽  
Author(s):  
J.S. Mccalmont ◽  
D. Robinson ◽  
K.M. Lakin ◽  
H.R. Shanks
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Film Growth ◽  
Dopant Concentration ◽  
Source Material ◽  
Cluster Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
P Type

ABSTRACTThin films of germanium have been prepared using an ultrahigh vacuum ionized-cluster beam (ICB) system. The dopant concentration of the films was varied by alloying the germanium source material with aluminum, a p-type dopant. X-ray diffraction analysis of the films has shown that an epitaxial (100) germanium film can be deposited on a (100) silicon substrate with a substrate temperature as low as 300°C. The results confirm that ICM deposition can be used to prepare epitaxial germanium films, but ionization of the clusters does not appear to affect the film growth.

Low-Temperature LPCVD MEMS Technologies

2002 ◽  
Vol 729 ◽  
Author(s):  
Roger T. Howe ◽  
Tsu-Jae King
Keyword(s):  
Silicon Germanium ◽  
Polycrystalline Silicon ◽  
Rf Mems ◽  
Sige Layer ◽  
Copper Metallization ◽  
Si Films ◽  
P Type ◽  
Mems Process ◽  
Post Deposition

AbstractThis paper describes recent research on LPCVD processes for the fabrication of high-quality micro-mechanical structures on foundry CMOS wafers. In order to avoid damaging CMOS electronics with either aluminum or copper metallization, the MEMS process temperatures should be limited to a maximum of 450°C. This constraint rules out the conventional polycrystalline silicon (poly-Si) as a candidate structural material for post-CMOS integrated MEMS. Polycrystalline silicon-germanium (poly-SiGe) alloys are attractive for modular integration of MEMS with electronics, because they can be deposited at much lower temperatures than poly-Si films, yet have excellent mechanical properties. In particular, in-situ doped p-type poly-SiGe films deposit rapidly at low temperatures and have adequate conductivity without post-deposition annealing. Poly-Ge can be etched very selectively to Si, SiGe, SiO2 and Si3N4 in a heated hydrogen peroxide solution, and can therefore be used as a sacrificial material to eliminate the need to protect the CMOS electronics during the MEMS-release etch. Low-resistance contact between a structural poly-SiGe layer and an underlying CMOS metal interconnect can be accomplished by deposition of the SiGe onto a typical barrier metal exposed in contact windows. We conclude with directions for further research to develop poly-SiGe technology for integrated inertial, optical, and RF MEMS applications.

Heavily carbon-doped p-type (In)GaAs grown by gas-source molecular beam epitaxy using diiodomethane

1995 ◽  
Vol 150 ◽  
pp. 221-226
Author(s):  
T. Tomioka ◽  
N. Okamoto ◽  
H. Ando ◽  
S. Yamaura ◽  
T. Fujii
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Carbon Doped ◽  
Gas Source ◽  
P Type

scholarly journals N. T. Wright on Paul the Pharisee and ancient Jews in exile

2016 ◽  
Vol 69 (4) ◽  
pp. 432-452
Author(s):  
Steve Mason
Keyword(s):  
Source Material ◽  
Fundamental Question ◽  
Topic Analysis

AbstractThis article examines two topics that emerge from N. T. Wright's Paul and the Faithfulness of the Gospel: Paul the Shammaite-zealot and the ‘great narrative’ of an Israel in exile, waiting for something. The perspective adopted is that of a historian, for whom the fundamental question is whether Wright's accounts approximate plausible reality two thousand years ago. With respect to the first topic, analysis of source material on the Pharisees in the pre-70 period renders Wright's association of Paul with the rabbinic ‘House of Shammai’ and zealotry doubtful in every part. Similar issues arise in relation to the second topic, where Wright's proposal is supported by a kind of proof-texting, without methodical concern for the nature, context, coherence, themes, rhetoric or meaning of texts in situ.

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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