Manufacturability of rapid-thermal oxidation of silicon: oxide thickness, oxide thickness variation, and system dependency

1993 ◽  
Vol 33 (13) ◽  
pp. 2073
1997 ◽  
Vol 470 ◽  
Author(s):  
G. C. Xing ◽  
D. Lopes ◽  
G. E. Miner

ABSTRACTIn this paper, we report the study of rapid thermal oxidation of silicon in N2O ambient using the Applied Materials RTP Centura rapid thermal processor, and N2O oxide thickness and compositional uniformities with respect to gas flow rate and wafer rotation speed as well as other process parameters. It was found that N2O oxide uniformity is strongly dependent on gas flow rate and wafer rotation speed in addition to process pressure. With optimized setting of the process parameters, excellent oxidation uniformities (one sigma < 1%) were obtained at atmospheric pressure N2O ambient. Nitrogen concentrations of such uniform oxides grown at 1050°C atmospheric pressure N2O oxidation processes were 1.7% for a 40Å oxide and 2.5% for a 60Å oxide, respectively, as characterized by SIMS analysis.


2004 ◽  
Vol 1 (2) ◽  
pp. 41-47
Author(s):  
A. G. Felício ◽  
José Alexandre Diniz ◽  
J. Godoy Fo. ◽  
I. Doi ◽  
M. A. A. Pudenzi ◽  
...  

Silicon oxynitride (SiOxNy) insulators have been obtained by nitrogen ion implantation into Si substrates prior to conventional or rapid thermal oxidation. These films have been used as gate insulators in nMOSFETs and MOS capacitors. nMOSFET electrical characteristics, such as field effect mobility between 390 cm2/Vs and 530 cm2/Vs, and sub-threshold slope between 70 mV/decade and 150 mV/decade, were obtained. MOS capacitors were used to obtain capacitance-voltage (C-V) and current-voltage (I-V) measurements. The Equivalent Oxide Thickness (EOT) of the films were obtained from C-V curves, resulting in values between 2.9 nm and 12 nm. SiOxNy gate insulators with EOT between 2.9 nm and 4.3 nm have presented gate leakage current densities between 3 mA/cm2 and 50 nA/cm2. The electrical characteristics were compared and correlated with the nitrogen concentration profiles at SiOxNy/Si of the structures, obtained by Secondary Ion Mass Spectrometry (SIMS).


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Youngseok Lee ◽  
Woongkyo Oh ◽  
Vinh Ai Dao ◽  
Shahzada Qamar Hussain ◽  
Junsin Yi

It is difficult to deposit extremely thin a-Si:H layer in heterojunction with intrinsic thin layer (HIT) solar cell due to thermal damage and tough process control. This study aims to understand oxide passivation mechanism of silicon surface using rapid thermal oxidation (RTO) process by examining surface effective lifetime and surface recombination velocity. The presence of thin insulating a-Si:H layer is the key to get highVocby lowering the leakage current (I0) which improves the efficiency of HIT solar cell. The ultrathin thermal passivation silicon oxide (SiO2) layer was deposited by RTO system in the temperature range 500–950°C for 2 to 6 minutes. The thickness of the silicon oxide layer was affected by RTO annealing temperature and treatment time. The best value of surface recombination velocity was recorded for the sample treated at a temperature of 850°C for 6 minutes at O2flow rate of 3 Lpm. A surface recombination velocity below 25 cm/s was obtained for the silicon oxide layer of 4 nm thickness. This ultrathin SiO2layer was employed for the fabrication of HIT solar cell structure instead of a-Si:H, (i) layer and the passivation and tunneling effects of the silicon oxide layer were exploited. The photocurrent was decreased with the increase of illumination intensity and SiO2thickness.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Gerald Gerlach ◽  
Karl Maser

Thermal oxidation of silicon belongs to the most decisive steps in microelectronic fabrication because it allows creating electrically insulating areas which enclose electrically conductive devices and device areas, respectively. Deal and Grove developed the first model (DG-model) for the thermal oxidation of silicon describing the oxide thickness versus oxidation time relationship with very good agreement for oxide thicknesses of more than 23 nm. Their approach named as general relationship is the basis of many similar investigations. However, measurement results show that the DG-model does not apply to very thin oxides in the range of a few nm. Additionally, it is inherently not self-consistent. The aim of this paper is to develop a self-consistent model that is based on the continuity equation instead of Fick’s law as the DG-model is. As literature data show, the relationship between silicon oxide thickness and oxidation time is governed—down to oxide thicknesses of just a few nm—by a power-of-time law. Given by the time-independent surface concentration of oxidants at the oxide surface, Fickian diffusion seems to be neglectable for oxidant migration. The oxidant flux has been revealed to be carried by non-Fickian flux processes depending on sites being able to lodge dopants (oxidants), the so-called DOCC-sites, as well as on the dopant jump rate.


1994 ◽  
Vol 342 ◽  
Author(s):  
C. B. Yarling ◽  
W. A. Keenan

ABSTRACTIn this study, 6-150mm p-type <100> wafers were cleaned, laser-scribed, and pre-process measured for stress. The wafers were then processed in a tungsten-halogen lamp RTP system with a target Rapid Thermal Oxidation (RTO) thickness of 100Å. Three categories of whole-wafer measurement techniques were used to characterize these wafers: optical, electrical, and mechanical. Optical inspection techniques included spectroscopic reflectometry (reflectivity), and a combination of beam profile reflectometry and beam profile ellipsometry (thickness). Electrical techniques included C-V plotting with a mercury probe (oxide thickness from Cmax, breakdown voltage, and interface trap density) as well as laser-induced photo-current scanning (minority carrier lifetime, minority-carrier diffusion-length). Mechanical inspection included wafer warpage and stress measurements as well as optical imaging inspection using the magic mirror method (damage and defects). Wafer measurements from these instruments (i.e., contour and 3-d maps) are used to characterize integrity of the RTO process.


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