Recently there has been an increased effort to develop cubic (3C-) SiC owning to its high electron mobility and high-saturation driftvelocity for the fabrication of high-power and high-temperature electronic devices. In this paper

we re po rt on the growth and electrical properties of voids-free n-3C-SiC/p-Si heter ojun ctions grown by LPCVD. The substrates are 2-inch p-type Si (100) wafers with resistivity of 10～12Ω·cm. SiH

4

C

2

H

4

and Pd-cell purified H

2

were used as precurso r gases with flow rates of 2

3sccm

and 3000 sccm

respectively. The LPCVD method at 5.32×10

4

Pa was employed to grow 3C-SiC epitaxial films. In order to prevent the formation of voids and obtain improved interface of 3C-SiC/Si

much at tention has been paid to the pretreatment and carbonization process of the subst rates. It was obtained that the SiC/Si interface is smooth and there is no obvious voids formed in the Si substrate surface. This result indicates that the out-diffusion of Si atoms from Si substrates was suppressed during the epitaxial gro wth of SiC at 1250℃. Hall-effect measurements were performed to investiga te the electrical properties of the grown films with about 1.5μm in thickness in the temperature range from 80 to 300K. The mobility was 408cm

2

/Vs with the carrier concentration was about 7.2×10

17

cm

-3

at room temperature. Hall mobility obeys the T-α law in temperature range from 300 to 130K

where the value of α is 1.2. The I-V

C-V

and the temperature dependence of I-V curves in 3C-SiC heterojunctions with indium (In) and aluminum (Al) electrical pads

respectively

were in vestigated. The heterojunctions diodes (HJDs) with 0.5～1mm

2

in area were obt ain ed by cleaving n-3C-SiC/p-Si. It was shown that with the introduction of a th in SiGe buffer layer between 3C-SiC and Si substrate

the reverse breakdown voltage and the current rectification ratio defined at ±1V bias were improved from 40V to 70V and from 3×10

2

to 7×10

3

respectively

for the diodes with In electrod es. The highest reverse breakdown voltage of approximately 100V was obtained in the 3C-SiC/p-Si heterojunctions with Al electrodes at room temperature. At low current densities the dependence of the forward current on voltage is exponential with the ideality factor of

n

=1.95 for both Al and In heterojunction diodes. The C-V characteristics of the diodes were linear in the

C

-2

-V co ordinates

which means that the obtained n-3C-SiC/p-Si heterojunctions were abrupt. A built-in voltage (

V

bi

) of 0.75V was obtained.