Materials Science in Semiconductor Processing 8 (2005) 121–124 Electrical properties of N atomic layer doped Si epitaxial films grown by ultraclean low-pressure chemical vapor deposition Youngcheon Jeong, Masao Sakuraba, Junichi Murota à Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan Available online 18 October 2004 Abstract Sheet carrier concentration and Hall mobility of the N atomic layer doped Si epitaxial films on Si(1 0 0) were obtained by Hall effect measurement. It is found that the N atoms act as a donor. Donor activation ratio tends to decrease with increasing N amount, and the typical ratio is about 0.4% at the N amount of 5  10 13 cm À2 /layer. Sheet carrier concentration in the temperature region higher than 160 K drastically increases with increase of the measurement temperature. The ionization energy of the donor level is estimated about 150–180 meV and almost independent of the N amount. Measured Hall mobility is as high as that of the uniformly P-doped Si with the P concentration of 10 16 –10 17 cm À3 in the measurement temperature range of 160–300 K. r 2004 Elsevier Ltd. All rights reserved. PACS: 61.72.Tt; 73.61.Cw; 71.55.Cn Keywords: Nitrogen atomic layer doping; Silicon epitaxial growth; Chemical vapor deposition; Hall mobility; Carrier concentration 1. Introduction Atomically controlled heterostructures with Si-based materials become increasingly attractive for future generations of integrated circuits and novel semicon- ductor device concepts [1–3]. Moreover, because locali- zation and condensation of strain and ionized impurities is expected to modulate transport and energy transition of electrons and holes, atomic-layer (AL) doping technology is important to create novel electronic properties. If N in Si crystal generates a donor level, several large ionization energies are predicted unlike the other group V impurities [5]. Therefore, creation of a deep donor band is expected by high-concentration N doping in Si. However, because of the complicated behavior of N incorporation in the ion implantation and annealing method, the actual donor ionization energy still remains unknown [6]. In the previous work, epitaxial growth of high quality N AL-doped Si on Si(1 0 0) has been performed by ultraclean low-tempera- ture low-pressure chemical vapor deposition (LPCVD) using NH 3 and SiH 4 reaction, and it is confirmed that the buried N doped layer thickness is less than 1 nm and the maximum N amount is 3  10 14 cm À2 [7]. In this paper, we describe electrical properties, e.g. temperature dependence of carrier concentration and Hall mobility, of the N AL-doped Si epitaxial films on Si(1 0 0). 2. Experimental N AL-doped Si epitaxial films were grown by an ultraclean hot-wall LPCVD system [8], and a ARTICLE IN PRESS 1369-8001/$-see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.mssp.2004.09.031 à Corresponding author. Tel./fax: +81222175548. E-mail address: murota@riec.tohoku.ac.jp (J. Murota).