In the present work we report an extended theoretical study to determine the charge state of the secondary particle emitted during the sputtering process. An investigation on the evolution of the ion-surface interaction along the trajectory of the moving particle away from the metal surface is highlighted. Accordingly, the charge exchange process between the emitted secondary particle and the solid surface is studied through out two mainly derived treatments, namely the semiclassical probability rate equation (based on the electron tunneling model) and the configurations interaction...