A matter wave associated with electron

According to Heisenberg uncertainty principle, if the matter wave associated with the electron is spread over the space, i.e, $∆\mathrm{x}\to \infty$, so, error in momentum, $∆\mathrm{p}\to 0$ will be zero, which is not possible. 

A matter wave associated with electron is a wave packet extending over some finite region of space. It is built up of wavelengths spread around some central wavelength.