Abstract: Method of depositing a film having a substantially uniform thickness by means of chemical vapor deposition, comprising: providing a reaction chamber; providing a substrate in said reaction chamber; subjecting the substrate to a series of deposition cycles, wherein each deposition cycle includes the steps of: (a) during a first time interval, supplying a first reactant to the reaction chamber; (b) during a second time interval, supplying a second reactant to the reaction chamber; and (c) during a third time interval, supplying neither the first nor the second reactant to the reaction chamber; wherein a start of the second time interval lies within the first time interval, such that a pre-exposure interval exists between a start of the first time interval and the start of the second time interval, during which pre-exposure interval the first reactant is supplied to the reaction chamber while the second reactant is not.