Vertical MOSFETs include a semiconductor substrate having a plurality of semiconductor mesas therein that are separated by a plurality of deep stripe-shaped trenches. The interposer has a higher thermal conductivity as compared to conventional interposers, thereby increasing the thermal dissipation through the interposer and enabling the device to cool more efficiently. Improper use by the players is prevented by separating the credits issuing from games by card or by tokens, respectively. A pair of dovetail slots extending perpendicular within the slotted head receives the locking cam when the driver inner shaft is rotated a quarter turn clockwise to fasten the surgical screw to the end of the driver.