Method of forming a Ti and a TiN layer on a semiconductor body by a sputtering process, comprising an additional step of cleaning the target.

摘要

A method of manufacturing semiconductor devices whereby first a Ti layer (8) and then a TiN layer (9) are deposited on slices of semiconductor material (20). The slices are placed on a support (30) one after the other in a deposition chamber (22), the support being positioned opposite a target of Ti (32) surrounded by an annular anode (31). Material is then sputtered off the target by means of a plasma (35) generated near the target. The plasma is generated in Ar during deposition of the Ti layer and in a gas mixture of Ar and N2 during deposition of the TiN layer. After the deposition of the TiN layer, before a next slice is placed in the chamber each time, the target is cleaned during an additional process step in that material is sputtered off the target by means of a plasma generated in Ar. The additional process step is ended the moment the target has regained a clean Ti surface again. It is achieved by this that an extra Ti layer comprising nitrogen is indeed deposited on the TiN layer during this additional process step, but that this is as thin as possible and accordingly contains as little free Ti as possible. Undesirable chemical reactions between free Ti and the conductive layers deposited on the layer comprising nitrogen are suppressed as much as possible thereby.