Search of Stop, Sbottom, $\tau$-Sneutrino, and Stau at an $e^+e^-$ Linear Collider with $\sqrt{s}=0.5 - 2$ TeV

We discuss pair production and decays of stops, sbottoms, $\tau$-sneutrinos, and staus in $e^+e^-$ annihilation in the energy range $\sqrt{s} = 500 GeV$ to 2 TeV. Numerical predictions within the Minimal Supersymmetric Standard Model (MSSM) for cross sections and decay rates are presented. We study the stop discovery potential for $\sqrt{s} = 500 GeV$ and $10 \fb^{-1}$ integrated luminosity for polarized e^- beams. Moreover, we give an estimate of the error of the soft-breaking stop and sbottom parameters that can be obtained by cross section measurements with polarized e^- beams.