Low-Temperature Epitaxial Growth of IN-Situ HeavilY B-Doped Si1-xGex, Films Using Ultraclean LPCVD

1998 ◽  
Vol 533 ◽  
Author(s):  
A. Morrya ◽  
M. Sakuraba ◽  
T. Matsuura ◽  
J. Murota ◽  
I. Kawashima ◽  
...  

AbstractIn-situ heavy doping of B into Si1-xGex epitaxial films on the Si(100) substrate have been investigated at 550°C in a SiH4(6.0Pa)-GeH4(0.1−6.0Pa)-B2H6(1.25 ×10−5−3.75 × 10−2Pa)-H2(17–24Pa) gas mixture by using an ultraclean hot-wall low-pressure CVD system. The deposition rate increased with increasing GeH4 partial pressure, and it decreased with increasing B2H6 partial pressure only at the higher GeH4 partial pressure. As the B2H6 partial pressure increased, the Ge fraction scarcely changed although the lattice constant of the film decreased. These characteristics can be explained by the suppression of both the SiH4 and GeH4 adsorption/reactions in a similar degree due to B2H6 adsorption on the Si-Ge and/or Ge-Ge bond sites. The B concentration in the film increased proportionally up to 1022cm3 with increasing B2H6 partial pressure.

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3733
Author(s):  
Jongwan Jung ◽  
Baegmo Son ◽  
Byungmin Kam ◽  
Yong Sang Joh ◽  
Woonyoung Jeong ◽  
...  

The key process steps for growing high-quality Si-based epitaxial films via reduced pressure chemical vapor deposition (RPCVD) are investigated herein. The quality of the epitaxial films is largely affected by the following steps in the epitaxy process: ex-situ cleaning, in-situ bake, and loading conditions such as the temperature and gaseous environment. With respect to ex-situ cleaning, dry cleaning is found to be more effective than wet cleaning in 1:200 dilute hydrofluoric acid (DHF), while wet cleaning in 1:30 DHF is the least effective. However, the best results of all are obtained via a combination of wet and dry cleaning. With respect to in-situ hydrogen bake in the presence of H2 gas, the level of impurities is gradually decreased as the temperature increases from 700 °C to a maximum of 850 °C, at which no peaks of O and F are observed. Further, the addition of a hydrogen chloride (HCl) bake step after the H2 bake results in effective in-situ bake even at temperatures as low as 700 °C. In addition, the effects of temperature and environment (vacuum or gas) at the time of loading the wafers into the process chamber are compared. Better quality epitaxial films are obtained when the samples are loaded into the process chamber at low temperature in a gaseous environment. These results indicate that the epitaxial conditions must be carefully tuned and controlled in order to achieve high-quality epitaxial growth.


1992 ◽  
Vol 275 ◽  
Author(s):  
Julia M. PhUlips ◽  
M. P. Siegal ◽  
S. Y. Hou ◽  
T. H. Tiefel ◽  
J. H. Marshall

ABSTRACTEpitaxial films of Ba2YCu3O7-δ (BYCO) as thin as 250 å A and with Jc's approaching those of the best in situ grown films can be formed by co-evaporating BaF2, Y, and Cu followed by a two-stage anneal. These results extend the work on films > 2000 Å thick by R. Feenstra et al. [J. Appl. Phys. 69, 6569 (1991)]. High quality films of these thicknesses become possible if low oxygen partial pressure [p(O2) = 4.3 Torr] is used during the high temperature portion cf the anneal (Ta). The BYCO melt line is the upper limit for Ta. The use of low p(O2) shifts the window for stable BYCO film growth to lower temperature, which allows the formation of smooth films with greater microstructural disorder than is found in films grown in p(O2) = 740 Torr at higher Ta. The best films annealed in p(O2)=4.3 Torr have Jc values a factor of four higher than do comparable films annealed in P2=740 Torr. The relationship between the T required to grow films with the strongest pinning force and p(O2) is log independent of growth method (in situ or situ) over a range of five orders of magnitude of P(O2).


1996 ◽  
Vol 143 (7) ◽  
pp. 2387-2391 ◽  
Author(s):  
C.‐L. Wang ◽  
S. Unnikrishnan ◽  
B.‐Y. Kim ◽  
D.‐L. Kwong ◽  
A. F. Tasch

1968 ◽  
Vol 23 (7) ◽  
pp. 1059-1067 ◽  
Author(s):  
Manfred Harsdorff

Special effects of gasadsorption on epitaxy were discussed in previous papers 1. In the present publication the influence of the adsorbed vapours on the epitaxial growth of fcc-metals on alkalihalides has been investigated in more detail. The results of the experiments demonstrate that the orientations of metal films are strongly influenced by the physical properties of the vapours the substrats are cleaved in. The thickness of the adsorbed layer is controlled by the dipole moment and the partial pressure of the vapours and additionnally by the substrat temperature and the deposition rate of the evaporated metal. Since the orientation of the metal films depends itself on the vapour covering of the cleavage planes, the orientation is also determined by these four quantities.


2010 ◽  
Vol 645-648 ◽  
pp. 925-928 ◽  
Author(s):  
Bharat Krishnan ◽  
Joseph Neil Merrett ◽  
Galyna Melnychuk ◽  
Yaroslav Koshka

In this work, the benefits of the low-temperature halo-carbon epitaxial growth at 1300oC to form anodes of 4H-SiC PiN diodes were investigated. Regular-temperature epitaxial growth was used to form an 8.6 μm-thick n-type drift region with net donor concentration of 6.45x1015 cm-3. Trimethylaluminum doping, in situ during blanket low-temperature halo-carbon epitaxial growth, was used to form heavily doped p-type layers. Forward I-V characteristics measured from diodes having different anode areas indicated that the new epitaxial growth technique provides anodes with low values of the series resistance, even without contact annealing. At room temperature, a 100 μm-diameter diode had a forward voltage of 3.75 V at 1000A/cm² before annealing and 3.23 V after annealing for 2 min at 750°C. The reverse breakdown voltage was more than 680 V (on average) in the devices without edge termination or surface passivation.


1991 ◽  
Vol 222 ◽  
Author(s):  
Maki Kawai ◽  
Masami Mori ◽  
Shunji Watabe ◽  
Ziyuan Liu ◽  
Yasunori Tabira ◽  
...  

ABSTRACTMolecular beam epitaxy of ultra thin films of Bi2Sr2CuO8-(2201 phase) is realized on the surface of SrTiO3 (100) and LaAlO3 (100) at the substrate temperature of 573 K, using 10-5Pa of NO2 as an oxidant. The film epitaxially grown from the surface of the substrate has identical in-plane lattice constant to the substrate itself. Such a growth can only be obtained on the substrate with similar lattice constant to those of the material to be formed. The crystallinity of the film strongly depended on the sequence of the metal depositions and the oxidation process. In the case of the Bi system, the elementary unit of the epitaxial growth has proved to be the subunit of the perovskite structure (Sr-Cu-Sr). The structure of the film grown on a substrate with large mismatch (MgO) is also discussed.


Sign in / Sign up

Export Citation Format

Share Document