Measurement of Hall Mobility in 4H-SiC for Improvement of the Accuracy of the Mobility Model in Device Simulation

High-dose aluminum-ion ͑Al + ͒ implantation into 4H-SiC (0001) and ͑1120͒ has been investigated. The dependences of the electrical properties on the implanted Al + dose and on the annealing time were examined by Hall-effect measurements. A low sheet resistance of 2.3 k⍀ / ᮀ (0.2 m deep) was obtained in a (0001) sample by implantation of Al + with a dose of 3.0ϫ 10 16 cm −2 at 500°C and a subsequent high-temperature anneal at 1800°C for a short time of 1 min. In the case of ͑1120͒ samples, even room-temperature implantation resulted in a low sheet resistance of 2.3 k⍀ / ᮀ (0.2 m-deep) after anneal at 1800°C. The Hall data are compared with the calculated values determined by using the doping-concentration dependent ionization energy of Al acceptors. The experimentally obtained free-hole concentrations agree well with the theoretically expected values. Hole mobilities are not as high as the empirical mobilities obtained in Al-doped epitaxial layers. The differences in the electrical properties between the experimental data and expected values are discussed.

Section: Discussion Of the Electrical Properties In P + -Sicmentioning

confidence: 99%

“…Using the parameters as given in Ref. In their report, 26 the parameters in the Eq. 7(b) is obtained.…”

Section: ͑2͒mentioning

confidence: 99%

Electrical activation of high-concentration aluminum implanted in 4H-SiC

Negoro

Kimoto

Matsunami

et al. 2004

“…The details of the growth conditions were reported in the previous paper. 36 One 10 m thick p-type 4H-SiC epilayer on an n + -type 4H-SiC(0001) substrate (sample number: No. 6) was purchased from Cree Res.…”

Section: Methodsmentioning

confidence: 99%

Dependence of acceptor levels and hole mobility on acceptor density and temperature in Al-doped p-type 4H-SiC epilayers

Matsuura

Komeda

Kagamihara

et al. 2004

Self Cite

The temperature-dependent hole concentration p͑T͒ and hole mobility p ͑T͒ are obtained in p-type 4H-SiC epilayers with several Al-doping densities. From p͑T͒, the densities and energy levels of acceptors are determined by the graphical peak analysis method (free carrier concentration spectroscopy: FCCS) without any assumptions regarding the acceptor species. In the heavily Al-doped case, the excited states of acceptors affect p͑T͒ because the Fermi level is located between the valence band maximum and the acceptor level (i.e., the ground state level of the acceptor), indicating that a distribution function for acceptors, which includes the influence of excited states of acceptors, should be required. Here, FCCS can determine acceptor densities and acceptor levels using any distribution function (e.g., the Fermi-Dirac distributing function or the distribution function including the influence of excited states). Two types of acceptor species are detected in the lightly Al-doped epilayers, while only one type of acceptor species is found in the heavily Al-doped epilayer. Some of the parameters required to simulate electric characteristics of 4H-SiC power electronic devices are obtained; (1) the dependence of each acceptor level on a total acceptor density and (2) the dependence of the hole mobility on temperature and total impurity density.

“…Three 10-m-thick n-type 4H-SiC epilayers with different N-doping densities were grown on p + -type 4H-SiC substrates, 15 and another three 10-m-thick n-type 4H-SiC epilayers grown on p + -type 4H-SiC substrates were pur-chased from Cree Inc. They were cut into a 3 ϫ 3-mm 2 size.…”

Section: Methodsmentioning

confidence: 99%

Parameters required to simulate electric characteristics of SiC devices for n-type 4H–SiC

Kagamihara¹,

Matsuura

Hatakeyama³

et al. 2004

Self Cite

Dependence of acceptor levels and hole mobility on acceptor density and temperature in Al-doped p -type 4H-SiC epilayersIn order to obtain some of the parameters required to simulate the electric characteristics of silicon carbide (SiC) power electronic devices in a wide temperature range from startup temperatures ͑ഛ30°C͒ to steady-operation temperatures ͑ജ200°C͒, we discuss the dependence of the two donor levels on the total donor density ͑N D ͒ as well as the dependence of the electron mobility on the total impurity density ͑N imp ͒ and operating temperature ͑T͒ in the n-type 4H-SiC. The temperature-dependent electron concentration n͑T͒ and electron mobility n ͑T͒ in the n-type 4H-SiC epilayers with several nitrogen-doping densities are obtained from the Hall-effect measurements. By the graphical peak analysis method (free carrier concentration spectroscopy: FCCS) without any assumptions regarding the donor species, the two types of donor species are detected from n͑T͒. Moreover, the energy level and density of each donor species are determined by the FCCS. Using these results, we obtain the parameters with which the dependence of each donor level on N D can be simulated. Using n ͑T͒ at T Ͼ 250 K, moreover, we obtain the parameters with which the dependence of the electron mobility on N imp and T can be simulated.