  Masses for the $(Q\bar{s})^{(*)}(\bar{Q}s)^{(*)}$ ($Q=c$ or $b$) molecular
states are systematically computed in the framework of QCD sum rules.
Technically, contributions of the operators up to dimension six are included in
operator product expansion (OPE). The numerical result $4.13\pm0.10 {GeV}$ for
$D_{s}^{*}\bar{D}_{s}^{*}$ agrees well with the mass $4143.0\pm2.9\pm1.2 {MeV}$
for Y(4140), which supports the $D_{s}^{*}\bar{D}_{s}^{*}$ molecular
configuration for Y(4140).
