Solid-State Electronics, Vol.46, No.9, 1367-1373, 2002
Development of plasma dielectric deposition method for increased pre-metal dielectric interfacial film stability
The pre-metal dielectric (PMD) layer consisting of two different dielectric films has the ability to both fill dielectric into the narrow features of shrinking designs and to provide smooth topography with contamination trapping abilities. Unfortunately. the same features that make the multiple film stacked PMD level Successful can lead to interface issues due to the unique properties of each film. An example of this is the delamination of the phosphorus doped silicate glass (PSG) from the high density plasma (HDP) layer of the HDP/PSG film stack composing the PMD level, When the characteristic signatures were noted during in-line inspection, this delamination or separation of the two films resulted in immediate product loss. This thesis presents a new PMD level that is resistant to the film delamination by the addition of an in situ intermediate USG layer at the onset of the PSG deposition. By providing a smooth dopant transition from HDP to PSG, this new level is not subject to the increased interface phosphorus and resulting attack and etchout during 100:1 HF clean processing, Results demonstrated that the new structure led to a more stable interface with increased product yield and no adverse effects noted upon on electrical testing. (C) 2002 Published by Elsevier Science Ltd.