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67 Modeling of boron and phosphorus implantation into (100) Germanium
Author(s): Y.S. Suh (Affiliation: Dept. of Phys., New Jersey Inst. of Technol., Newark, NJ, USA), M.S. Carroll, R.A. Levy, M.A. Sahiner, G. Bisognin, C.A. King
Journal: IEEE Trans. Electron Devices (USA), vol.52, no.1, p.91-8 (Jan. 2005)
Publisher: IEEE, USA
Language: English
ISSN: 0018-9383, Full text
Document type: Journal article
Abstract: Boron and phosphorus implants into germanium and silicon with energies from 20 to 320 keV and ion doses from 5×1013 to 5×1016 cm-2 were characterized using secondary ion mass spectrometry. The first four moments of all implants were calculated from the experimental data. Both the phosphorus and boron implants were found to be shallower in the germanium than in the silicon for the same implant parameters and high hole concentrations, as high as 2×1020 cm-3, were detected by spreading resistance profiling immediately after boron implants without subsequent annealing. Channeling experiments using nuclear reaction analysis also indicated high substitutional fractions (~19%) even in the highest dose case immediately after implant. A greater straggle (second moment) is, however, observed in the boron implants in the germanium than in the silicon despite having a shorter projected range in the germanium. Implant profiles predicted by Monte Carlo simulations and Lindhard-Scharff-Schiott theory were calculated to help clarify the implant behavior. Finally, the experimentally obtained moments were used to calculate Pearson distribution fits to the boron and phosphorus implants for rapid simulation of nonamorphizing doses over the entire energy range examined (17 refs.)
Inspec No.: 8249848
68 Effects of annealing on charge in HfO2 gate stacks
Author(s): Z. Zhang, M. Li, S.A. Campbell (Affiliation: Dept. of Electr. & Comput. Eng., Univ. of Minnesota, Minneapolis, MN, USA)
Journal: IEEE Electron Device Lett. (USA), vol.26, no.1, p.20-2 (Jan. 2005)
Publisher: IEEE, USA
Language: English
ISSN: 0741-3106, Full text
Document type: Journal article
Abstract: This letter presents a systematic investigation of charge in HfO 2 gate stacks. Assuming that the majority of charge is associated with the stack interfaces, it is found that the charge at the HfO2/interfacial layer (IL) interface is negative while the charge at the Si/IL interface is positive. In general, the calculated charge densities at both interfaces are of order 1012 cm-2. A forming gas anneal (FGA) reduces the interface charge greatly at both interfaces. However, the FGA temperature does not have much effect on the charge density. The effects of post deposition anneal at various temperatures and under various atmospheres are also studied. Its found that a high temperature dilute oxidizing atmosphere anneal reduces the charge at both interfaces (16 refs.)
Inspec No.: 8250019
69 Applications of plasma technique for shallow ion implantation
Author(s): R. Gronau, J. Szmidt (Affiliation: Inst. Mikroelektroniki i Optoelektroniki, Politech. Warszawska, Warsaw, Poland), T. Gotszalk, A. Marendziak, P. Konarski, A. Rylski
Journal: Elektronika (Poland), vol.45, no.10, p.11-12 (2004)
Publisher: SIGMA NOT, Poland
Language: Polish
ISSN: 0033-2089
Document type: Journal article
Abstract: The research of a phenomenon of shallow carbon ion implantation into silicon substrate and correlation between the implantation process and silicon substrate properties was described in this article. The implantation was carried out in the RF plasma environment during carbon layer deposition in course of plasma immersion ion implantation (Pill) process. Electronic parameters of MOS capacitors fabricated on undoped substrate were compared to the ones produced on carbon implanted wafer. This was done in order to determine properties of substrates surface neighbouring region. The surface of post implanted silicon substrate was investigated by atomic force microscopy (AFM), secondary ion mass spectroscopy (SIMS) and Auger spectroscopy (AES). It was stated that the shallow ion implantation process is possible on basis of analysis of electronic parameters (1 refs.)
Inspec No.: 8248404
70 Temperature calculation of ion implanted silicon during rapid thermal annealing using iodine-tungsten lamp
Author(s): Luo Yi-min (Affiliation: Sch. of Phys. Sci. & Technol., Central South Univ., Changsha, China), Chen Zhenhua, Huang Pei-yun
Journal: J. Central South Univ. Technol., Sci. Technol. (China), vol.35, no.4, p.548-51 (2004)
Publisher: Editorial Committee of J. of Central South Univ. of Technol, China
Language: Chinese
ISSN: 1672-7207
Document type: Journal article
Abstract: Rapid thermal annealing after ion implantation induces solid phase epitaxy growth. Annealing temperature and its distribution influence greatly on crystallized speed of SPEG and quality of annealed materials. The relationship among annealing temperature, substrate temperature and power of iodine-tungsten lamp during rapid thermal annealing of ion implanted silicon by an isothermal model is analysed, according to equilibrium between incident power density and radiative power density. The results show that in the range of substrate temperature from 300 K to 1 070 K, the main factor that influences annealing temperature is power of iodinetungsten lamp rather than substrate temperature. The critical power of iodine-tungsten lamp for silicon to be molten is 2. 6 kW, the theoretical data approximates the experimental data (15 refs.)
Inspec No.: 8250121
71 An algorithm for smoothing three-dimensional Monte Carlo ion implantation simulation results
Author(s): C. Heitzinger, A. Hossinger, S. Selberherr (Affiliation: Inst. for Microelectron., Tech. Univ. of Vienna, Wien, Austria)
Journal: Math. Comput. Simul. (Netherlands), vol.66, no.2-3, p.219-30 (29 June 2004)
Publisher: Elsevier, Netherlands
Language: English
ISSN: 0378-4754, Full text
Document type: Journal article
Abstract: We present an algorithm for smoothing results of three-dimensional Monte Carlo ion implantation simulations and translating them from the grid used for the Monte Carlo simulation to an arbitrary unstructured three-dimensional grid. This algorithm is important for joining various simulations of semiconductor manufacturing process steps, where data have to be smoothed or transferred from one grid to another. Furthermore, different grids must be used since using orthogrids is mandatory because of performance reasons for certain Monte Carlo simulation methods. The algorithm is based on approximations by generalized Bernstein polynomials. This approach was put on a mathematically sound basis by proving several properties of these polynomials. It does not suffer from the ill effects of least squares fits of polynomials of fixed degree as known from the popular response surface method. The smoothing algorithm which works very fast is described and in order to show its applicability, the results of smoothing a three-dimensional real world implantation example are given and compared with those of a least squares fit of a multivariate polynomial of degree 2, which yielded unusable results (21 refs.)
Inspec No.: 8251680
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