In many plasma deposition systems it is necessary to monitor and control the flux of species bombarding the substrate in order to control film growth kinetics. The ability of controlling this growth can lead to desirable changes in the films structure and properties. Presented in the following thesis is a report on the design and construction of a variable balance magnetron sputtering system with an energy resolved mass spectrometer. Also reported is the characterisation of the deposition process at various degrees of magnetron unbalance. This unbalance is controlled by varying the current / in a solenoid, which is the central pole of a cylindrical magnetron, place behind the sputtering target. The current 1 is found to ultimately control the deposition conditions at constant pressures and levels of discharge current. It is also found to directly control the energy and flux of species bombarding the substrate during deposition. This data and the effects on the film properties are reported on.