This paper investigates the short scale structures that are observed in the electric field during crossings of the quasi-perpendicular bow shock using data from the Cluster satellites. These structures exhibit large amplitudes, as high as 70 m Vm<sup>-1</sup> and so make a significant contribution to the overall change in potential at the shock front. It is shown that the scale size of these short-lived electric field structures is of the order of a few <i>c</i>/ω<sub><i>pe</i></sub>. The relationships between the scale size and the upstream Mach number and θ<sub><i>Bn</i></sub> are studied. It is found that the scale size of these structures decreases with increasing plasma β and as θ<sub><i>Bn</i></sub>→90°. The amplitude of the spikes remains fairly constant with increasing <i>M<sub>a</sub></i> and appears to increase as θ<sub><i>Bn</i></sub>→90°.