Ultra-Shallow Diffused Emitter-Base Profiles Fabricated by Rapid Thermal Processing for High Speed Bipolar Devices

1989 ◽  
Vol 146 ◽  
Author(s):  
J. E. Urner ◽  
C. I. Drowley ◽  
P. Vande Voorde ◽  
A. Kermani

ABSTRACTThe development of next-generation high-speed bipolar devices depends critically on reproducible shallow dopant profiles, with base and emitter widths considerably less than 1000 Angstroms. Sequential diffusion of boron and arsenic from implanted polysilicon is a promising means of producing such shallow emitter-base profiles. The restricted thermal budget required to reproducibly form such shallow junctions severely limits the use of conventional furnaces. We report the formation of extremely shallow emitter-base profiles using rapid thermal processing (RTP) in a double-diffused polysilicon emitter process. Polysilicon was implanted with various doses of BF2 and subjected to a conventional furnace anneal at 900ºC. This process was followed by As implantation and furnace anneal at 900ºC or RTP at 10500C or 1100ºC. A range of emitter-base profiles was generated with emitter and base widths ranging from 350-800A. Emitter-base profiles were measured using low-energy Secondary Ion Mass Spectrometry (SIMS), after removal of the polysilicon to improve depth resolution. Deconvolution of the instrumental broadening function allowed extraction of base and emitter widths as well as the boron concentration in the base. Variation of the profiles is discussed as a function of anneal times and implant dose. Modified SUPREM III parameters are obtained for diffusivities under these RTP conditions. The implications for high speed bipolar device fabrication will be presented.

2001 ◽  
Vol 08 (05) ◽  
pp. 569-573
Author(s):  
R. LIU ◽  
K. H. KOA ◽  
A. T. S. WEE ◽  
W. H. LAI ◽  
M. F. LI ◽  
...  

As the gate dielectric for ULSI MOS devices scales in the ultrathin regime, it is fabricated increasingly with silicon oxynitride instead of silicon dioxide films. One way to obtain silicon oxynitride films is the rapid thermal oxidation of silicon in NO (RTNO). Earlier RTNO growth studies were not sufficiently comprehensive as well as limited by temperature uncertainty and nonuniformity across the wafer. Using a state-of-the-art rapid thermal processing (RTP) system, RTNO growth characteristics at oxidation pressures of 100 and 760 Torr, oxidation temperatures from 900 to 1200°C and oxidation times from 0 to 480 s were obtained and investigated. Anomalies in the growth characteristics were observed. It was also demonstrated that secondary ion mass spectrometry (SIMS) using the MCs + method could be used to accurately determine the depth distribution of N in ultrathin silicon oxynitride films.


1985 ◽  
Vol 45 ◽  
Author(s):  
J.C. Bean ◽  
A.T. Fiory ◽  
L.C. Hopkins

ABSTRACTEpitaxial Ge-Si alloy films were grown on Si(100) by molecular beam epitaxy, subsequently given a shallow P implant, and subjected to rapid thermal processing. Heat treatment causes solid-phase epitaxial regrowth of the amorphized implanted layer similar to the case of pure Ge. Phosphorus redistribution, loss, and trapping at the Ge-Si/Si interface are also observed. Anomalous electrical activation is observed for P concentrations below 1 at.%, where the-carriers are either trapped or compensated at room temperature, but not below 100K. Analyses were carried out by Rutherford backscattering and channeling, secondary ion mass spectrometry, and temperature-dependent electrical transport.


1991 ◽  
Vol 224 ◽  
Author(s):  
C. Schietinger ◽  
B. Adams ◽  
C. Yarling

AbstractA novel wafer temperature and emissivity measurement technique for rapid thermal processing (RTP) is presented. The ‘Ripple Technique’ takes advantage of heating lamp AC ripple as the signature of the reflected component of the radiation from the wafer surface. This application of Optical Fiber Thermometry (OFT) allows high speed measurement of wafer surface temperatures and emissivities. This ‘Ripple Technique’ is discussed in theoretical and practical terms with wafer data presented. Results of both temperature and emissivity measurements are presented for RTP conditions with bare silicon wafers and filmed wafers.


2019 ◽  
Vol 34 (5) ◽  
pp. 848-853 ◽  
Author(s):  
Paweł Piotr Michałowski ◽  
Piotr Caban ◽  
Jacek Baranowski

A refined SIMS procedure allows reaching atomic resolution and characterization of each layer in van der Waals structures separately.


2006 ◽  
Vol 527-529 ◽  
pp. 625-628
Author(s):  
Hun Jae Chung ◽  
Sung Wook Huh ◽  
A.Y. Polyakov ◽  
Saurav Nigam ◽  
Qiang Li ◽  
...  

Undoped 6H- and 4H-SiC crystals were grown by Halide Chemical Vapor Deposition (HCVD). Concentrations of impurities were measured by various methods including secondary-ion-mass spectrometry (SIMS). With increasing C/Si ratio, nitrogen concentration decreased and boron concentration increased as expected for the site-competition effect. Hall-effect measurements on 6H-SiC crystals showed that with the increase of C/Si ratio from 0.06 to 0.7, the Fermi level was shifted from Ec-0.14 eV (nitrogen donors) to Ev+0.6 eV (B-related deep centers). Crystals grown with C/Si > 0.36 showed high resistivities between 1053 and 1010 4cm at room temperature. The high resistivities are attributed to close values of the nitrogen and boron concentrations and compensation by deep defects present in low densities.


2019 ◽  
Vol 25 (2) ◽  
pp. 517-523
Author(s):  
Alain Portavoce ◽  
Khalid Hoummada ◽  
Lee Chow

AbstractFor a long time, secondary ion mass spectrometry (SIMS) was the only technique allowing impurity concentrations below 1 at% to be precisely measured in a sample with a depth resolution of few nanometers. For example, SIMS is the classical technique used in microelectronics to study dopant distribution in semiconductors and became, after radiotracers were forsaken, the principal tool used for atomic transport characterization (diffusion coefficient measurements). Due to the lack of other equivalent techniques, sometimes SIMS could be used erroneously, especially when the analyzed solute atoms formed clusters, or for interfacial concentration measurements (segregation coefficient measurements) for example. Today, concentration profiles measured by atom probe tomography (APT) can be compared to SIMS profiles and allow the accuracy of SIMS measurements to be better evaluated. However, APT measurements can also carry artifacts and limitations that can be investigated by SIMS. After a summary of SIMS and APT measurement advantages and disadvantages, the complementarity of these two techniques is discussed, particularly in the case of experiments aiming to measure diffusion and segregation coefficients.


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