IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Applied Surface Analysis Tuesday Sessions
       Session AS-TuA

Invited Paper AS-TuA1
Sputtering-induced Effects in Ultra Shallow Depth Profiling

Tuesday, October 30, 2001, 2:00 pm, Room 134

Session: Depth Profiling I
Presenter: A.T.S. Wee, National University of Singapore
Authors: A.T.S. Wee, National University of Singapore
C.M. Ng, National University of Singapore
R. Liu, National University of Singapore
Correspondent: Click to Email
Following the increasingly stringent requirements in the characterization of sub-micron IC devices, a good understanding of various factors affecting ultra shallow depth profiling in secondary ion mass spectrometry (SIMS) becomes crucial. Achieving high depth resolution (of the order of 1 nm) is becoming critical in the semiconductor industry today, and various methods have been developed to optimize depth resolution. In this paper, I will discuss ultra shallow SIMS depth profiling in several important semiconductor systems, namely B delta-doped Si, SiGe heterostructures and ultrathin oxynitride gate films. Results from both dynamic SIMS (Cameca IMS 6f) and TOF-SIMS (ION-TOF IV) will be presented. By using low energy (e.g. 500 eV) O@sub 2@@super +@ and Cs@super +@ beams, the relationship between depth resolution of the delta layers and surface topography measured by atomic force microscopy (AFM) is studied. The effects of oxygen flooding and sample rotation, used to suppress surface roughening, have also been investigated. X-ray photoelectron spectroscopy (XPS) is used to characterize the surface chemical composition of the crater bottom and a direct relationship between the surface chemical state and surface roughness is established. The various factors that limit the depth resolution in ultra shallow SIMS depth profiling are discussed.