Method for a reactive surface treatment of a workpiece and a treatment chamber for practicing such method

A method for treating a surface by reactive process, comprising the steps of:

• (a) providing several gas inlet openings into a reactor vessel;
• (b) providing several gas retrieving openings from said reactor vessel;
• said gas inlet and gas retrieving openings being arranged neighboring each other and distributed along a surface opposite said surface to be treated, said openings each having central axes directed substantially perpendicular to said surface to be treated, each gas inlet opening being associated with a gas retrieving opening to define a pair of openings;
• (c) feeding a gas mixture having a reactive gas to said gas inlet openings for injecting said gas towards said surface to be treated;
• (d) withdrawing gas having reaction products resulting from a reactive treatment of said surface to be treated out of said reactor vessel through said gas retrieving openings;
• (e) controlling an effect of a treatment on an area being treated by a given pair of openings by adjusting one of a group of variables, said variables including:
• selecting, as a first variable, a distance between a gas inlet opening and a gas retrieving opening forming an opening pair, and selecting, as a second variable, a distance of said opening pair to an area of said surface to be treated opposite said pair, and selecting as a third and a fourth variable, a gas injecting rate and a gas withdrawing rate, respectively, whereby an adjustment of at least one of said variables results in a variation of a treatment effect by reactive process of the surface being treated at said area, which variation is larger than variations of a treatment effect of a surface being treated occurring at surface areas adjacent said area disposed opposite said given pair of openings which variations result from said adjustment.