Title :
A characterization of PECVD TEOS BPSG planarity and metal-field Vt on a submicron CMOS EPROM
Author :
Ibok, Effiong E. ; Garg, Shyam ; Lee, Eddie ; Banon, John O.
Author_Institution :
Adv. Micro Devices Inc., Austin, TX, USA
Abstract :
The planarity and metal-field Vt of PECVD TEOS BPSG were studied on an 0.8 micron technology CMOS EPROM structure. Film planarity was found to depend, primarily on boron concentration for any given thickness. A correlation between boron concentration, flow angle over an isolated poly lead and planarity in the array is established. Array planarity was found to improve with thickness. However, no noticeable difference in planarity was observed between a 7.5 kA film and a 9 kA film. Perfect array planarity is demonstrated. A correlation between film thickness and contact aspect ratio is also presented. A correlation between film oxide charge as measured by surface charge analysis and metal-field Vt is established. The n-channel field Vt decreased with increase in oxide charge, which indicates the charge is positive. The charge is concluded to be restricted to the BPSG layer
Keywords :
CMOS integrated circuits; EPROM; borosilicate glasses; integrated circuit technology; integrated memory circuits; metallisation; phosphosilicate glasses; plasma CVD; 0.8 micron; B2O3-P2O5-SiO2; BPSG planarity; PECVD TEOS BPSG; contact aspect ratio; film oxide charge; film thickness; flow angle; metal-field Vt; metallization; plasma enhanced deposition; submicron CMOS EPROM; Boron; CMOS technology; Charge measurement; Current measurement; EPROM; Isolation technology; Metallization; Sputter etching; Sputtering; Threshold voltage;
Conference_Titel :
VLSI Multilevel Interconnection Conference, 1991, Proceedings., Eighth International IEEE
Conference_Location :
Santa Clara, CA
Print_ISBN :
0-87942-673-X
DOI :
10.1109/VMIC.1991.153028
