Thermally Driven In-Situ Removal of Native Oxide Using Anhydrous Hydrogen Fluoride

1993 ◽  
Vol 318 ◽  
Author(s):  
Pushkar P. Apte ◽  
Heungsoo Park ◽  
Krishna C. Saraswat ◽  
C. R. Helms
Keyword(s):  
Hydrogen Fluoride ◽  
Native Oxide ◽  
Epitaxial Silicon ◽  
Crystal Silicon ◽  
Silicon Deposition ◽  
Native Oxides ◽  
Anhydrous Hydrogen Fluoride ◽  
Thermally Driven ◽  
Oxide Removal

ABSTRACTIn-situ native-oxide removal is critical for epitaxial single-crystal silicon deposition, for polysilicon emitters and contacts and for ultrathin gate dielectric films in integrated circuit (IC) fabrication. We have developed an in-situ, thermally-driven, anhydrous hydrogen fluoride (AHF)-based native-oxide removal technique in which the wafer is treated by AHF at low temperatures (300-400°C) and a short (10 sec) 950°C ‘spike’ in AHF-H2 immediately prior to Si deposition. This process removes native oxides formed by standard wet cleans such as HC1:H202 and NH4OH:H202, as well as native oxides formed by the clean-room ambient. Further, the technique is an effective pre-clean for both polysilicon and epitaxial silicon deposition. This flexibility, combined with other salient features such as simplicity and a low thermal budget, make the process eminently suited for IC fabrication.

Polysilicon Emitter Transistors Manufactured using a Novel Limited Reaction Processing System

1989 ◽  
Vol 146 ◽  
Author(s):  
Fred Ruddell ◽  
Colin Parkes ◽  
B Mervyn Armstrong ◽  
Harold S Gamble
Keyword(s):  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Processing System ◽  
Bipolar Transistors ◽  
Native Oxide ◽  
Plasma Oxidation ◽  
Oxide Removal ◽  
Polysilicon Emitter ◽  
Reaction Processing

ABSTRACTThis paper describes a LPCVD reactor which was developed for multiple sequential in-situ processing. The system is capable of rapid thermal processing in the presence of plasma stimulation and has been used for native oxide removal, plasma oxidation and silicon deposition. Polysilicon layers produced by the system are incorporated into N-P-N polysilicon emitter bipolar transistors. These devices fabricated using a sequential in-situ plasma clean-polysilicon deposition schedule exhibited uniform gains limited to that of long single crystal emitters. Devices with either plasma grown or native oxide layers below the polysilicon exhibited much higher gains. The suitability of the system for sequential and limited reaction processing has been established.

Heteroepitaxial Metal Oxides on Silicon by Laser Ablation

1990 ◽  
Vol 191 ◽  
Author(s):  
D. B. Fenner ◽  
D. K. Fork ◽  
G. A. N. Connell ◽  
J. B. Boyce ◽  
F. A. Ponce ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Single Crystal Silicon ◽  
Native Oxide ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Crystal Silicon ◽  
Ybco Films ◽  
Zero Resistance ◽  
High Degree

ABSTRACTThin epitaxial films of cubic - fluorite structured PrO2 and YSZ (yttria- stabilized zirconia) were grown on single crystal silicon substrates using the laser ablation - deposition technique. X-ray diffraction theta two - theta, omega rocking and phi scans indicate a high degree of epitaxial orientation of the films to the Si lattice. The highest quality of epitaxy was obtained with the PrO2 [111] oriented normal to Si(111) surfaces and the cubic YSZ [100] normal to Si(100) surfaces. For both PrO2 and YSZ, high epitaxial quality required the removal of the Si native oxide prior to deposition and careful control of the deposition environment. It was further found that the YSZ films on Si(100) were an excellent surface for subsequent laser ablation of YBCO films by the usual in situ process. The resistivity of this YBCO was ≈ 250 micro-ohm-cm at 300 K, extrapolated to the resistivity -temperature origin, showed a sharp transition to zero resistance at ≈ 85 K and was nearly identical to high quality YBCO films deposited on (bulk) YSZ substrates.

AFM analysis of HF Vapor Cleaned SiO2 Surfaces

1997 ◽  
Vol 477 ◽  
Author(s):  
R. J. Carter ◽  
E. J. Bergman ◽  
D. R. Lee ◽  
J. Owyang ◽  
R. J. Nemanich
Keyword(s):  
Ambient Pressure ◽  
Etching Process ◽  
Native Oxide ◽  
Average Height ◽  
Force Microscopy ◽  
Native Oxides ◽  
Atomic Force ◽  
Thermal Oxide ◽  
Afm Analysis ◽  
Oxide Removal

ABSTRACTSi(100) surfaces were cleaned using HF/IPA vapor chemistries at ambient pressure and temperature with nitrogen as the carrier gas. Three distinct cases for oxide removal were studied: vapor etching of native oxides, RCA chemical oxides, and thermal oxides. Atomic Force Microscopy (AFM) was used to characterize the surface morphology after the HF vapor etching process. The AFM indicated exaggerated peaks in random places on the surface, These peaks were identified as residue remaining after the vapor etching process. The average lateral width of the peaks were ∼ 50 nm. The average height of the peaks for native and chemical oxide etched surfaces was relatively the same, approximately 8 nm. The average height of the peaks after thermal oxide removal was significantly smaller, approximately 1–2 nm. Peak density for native oxide etched surfaces was significantly greater than chemical or thermal oxide etched surfaces. We suggest that impurities in the oxide contribute to residue formation on the surface.

Substrate Induced Crystallinity in Reactive Sputter Deposition of Hydrogenated Silicon

1991 ◽  
Vol 219 ◽  
Author(s):  
G. F. Feng ◽  
M. Katiyar ◽  
J. R. Abelson ◽  
N. Maley
Keyword(s):  
Hydrogen Pressure ◽  
Crystalline Silicon ◽  
Native Oxide ◽  
Crystal Silicon ◽  
Hydrogenated Silicon ◽  
Reactive Sputter Deposition ◽  
Wide Range ◽  
Multi Wavelength ◽  
Fraction Increase

ABSTRACTWe use in situ multi-wavelength ellipsometry to study growth of hydrogenated amorphous silicon and crystalline silicon deposited by reactive DC magnetron sputtering. Crystal silicon covered with native oxide and oxide free crystal silicon are used as substrates. Deposition on c-Si/ox over a wide range of conditions yields amorphous films, and the growth proceeds with formation of small islands, regardless of hydrogen partial pressure. Growth on oxide free c-Si, on the other hand, is hydrogen dependent. Even at a low hydrogen pressure, a layer with mixed phase of c-Si and a-Si:H begin to appear near the c-Si substrate. This layer thickness and its c-Si fraction increase with hydrogen pressure. Bombardment of growing surface by energetic particles, both silicon and hydrogen species, appears to lead to the crystallization.

Demonstration of Multiprocessing by Silicon Epitaxy Following In-Situ Cleaning

1991 ◽  
Vol 224 ◽  
Author(s):  
Pushkar P. Apte ◽  
Ramnath Venkatraman ◽  
Krishna C. Saraswat ◽  
Mehrdad M. Moslehi ◽  
Richard Yeakley
Keyword(s):  
Semiconductor Manufacturing ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Crystal Silicon ◽  
Silicon Epitaxy ◽  
Anhydrous Hydrogen Fluoride ◽  
Manufacturing Techniques ◽  
Specific Manifestation ◽  
Low Thermal Budget

AbstractConventional semiconductor manufacturing techniques may be unable to meet technological demands in certain cases, and alternatives need to be investigated. We propose in situ sequential processing, which we define as ‘multiprocessing’, as a possible innovation. We demonstrate a specific manifestation of multiprocessing, namely the integration of a novel in situ pre-clean using anhydrous hydrogen fluoride with chemical vapor deposition of silicon, leading to the growth of high-quality single-crystal silicon epitaxy. Further, we show that the multiprocessing technology is viable for manufacturing, since it is simple, rapid, has a low thermal budget and does not suffer from cross-contamination. Finally, we discuss the possible role of multiprocessing in semiconductor manufacturing.

Thin oxides with in situ native oxide removal [n-MOSFETs]

1997 ◽  
Vol 18 (9) ◽  
pp. 417-419 ◽  
Author(s):  
A. Chin ◽  
W.J. Chen ◽  
T. Chang ◽  
R.H. Kao ◽  
B.C. Lin ◽  
...  
Keyword(s):  
Native Oxide ◽  
Oxide Removal

Electron-Beam Assisted CVD of Silicon Homoepitaxial Films

1988 ◽  
Vol 129 ◽  
Author(s):  
J. P. West ◽  
C. B. Fleddermann
Keyword(s):  
Electron Beam ◽  
Single Crystal Silicon ◽  
Beam Current ◽  
Silicon Substrates ◽  
Beam Diameter ◽  
Epitaxial Silicon ◽  
Large Area ◽  
Plasma Etch ◽  
Crystal Silicon

ABSTRACTThe use of a wide-area electron beam to aid the deposition of epitaxial silicon films has been studied. The electron beam used in this study is generated using a cold cathode, abnormal-glow discharge which allows a wide variation of electron energy and beam current. Depositions are performed on single crystal silicon substrates which are prepared using standard wet chemical silicon cleaning techniques and an in situ plasma etch using nitrogen tri-fluoride diluted in hydrogen. The beam diameter is approximately 10 cm and can readily be scaled up to accommodate larger diameters, allowing great potential for large area single wafer deposition. Using electron beams generated in this system, we have demonstrated enhanced growth rates and improved crystalline quality for films grown withelectronbeam enhancement.

Sign in / Sign up

Export Citation Format

Share Document