The surface wettability of the native Si oxide surfaces were tuned by chemical adsorption of 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) molecules through thermal CVD method at different temperature. Water contact angle measurements revealed that the water contact angles of the TMCTS-modified Si oxide surfaces at the temperature of 333-373 K were found to be in the range of 92 +/- 2-102 +/- 2 degrees. The advancing and receding water contact angle of the surface prepared at 333 K were found to be 97 +/- 2/92 +/- 2 degrees, showing low contact angle hysteresis surface. The water contact angles of the surfaces prepared at the temperature of 373-413 K increased with an increase in the treatment temperature. When the treatment temperature was more than 423 K, the water contact angles of TMCTS-modified surfaces were found to become more than 150 degrees, showing superhydrophobic surface. AFM study revealed that the surface roughness of the TMCTS-modified surface increased with an increase in the treatment temperature. This geometric morphology enhanced the surface hydrophobicity. The surface roughness could be fabricated due to the hydrolysis/condensation reactions in the gas phase during CVD process. The effect of the treatment temperature on the reactivity of the TMCTS molecules were also investigated using a thermogravimetric analyzer. (C) 2016 Elsevier B.V. All rights reserved.