Effect of oxygen impurity on microstructure and boron penetration in a BF{sub 2}{sup +} implanted LPCVD stacked amorphous silicon p{sup +} gated PMOS capacitor

Journal Article · Sat Jul 01 04:00:00 EDT 1995 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.2044316· OSTI ID:99624

Lin, C Y ^[1]; Pan, F M; Chou, P F ^[2]; Chang, C Y ^[1]

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1. National Chiao-Tung Univ., Hsinchu (Taiwan, Province of China). Institute of Electronics
2. National Nano Device Laboratory, Hsinchu (Taiwan, Province of China)

Secondary ion mass spectroscopy (SIMS) and transmission electron microscopy have been used to characterize microstructure and boron penetration in BF{sup +}{sub 2} implanted amorphous silicon p{sup +} gated metal oxide semiconductor (PMOS) capacitors, in which oxygen is inadvertently introduced in the gate area during the low pressure chemical vapor deposition (LPCVD) process. Oxygen impurity is found to be incorporated in the LPCVD deposited amorphous silicon film by SIMS. During the break between the two successive depositions for the stacked amorphous silicon (SAS) gate, an ultrathin oxide layer is formed at the interface between the two LPCVD amorphous silicon layers. The two thinner layers lead to smaller grains in the SAS structure. The interfacial oxide layer is a diffusion barrier for oxygen, which causes a higher oxygen concentration and, in turn, retards the crystallization in the SAS structure. Both the interfacial oxide layer and the gate oxide can dissolve a significant amount of fluorine after annealing. Reduction of free fluorine near or in the gate oxide due to fluorine dissolution in the interfacial oxide layer plays a crucial role for suppressing the boron penetration in the SAS capacitor.

• Sponsoring Organization: USDOE
• OSTI ID: 99624
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 7 Vol. 142; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON FLUORIDES
CAPACITORS
ION IMPLANTATION
ION MICROPROBE ANALYSIS
MASS SPECTROSCOPY
MICROSTRUCTURE
MOSFET
POLYCRYSTALS
SILICON
SILICON OXIDES
VAPOR DEPOSITED COATINGS