학술논문

Uniform spike anneals of ultra low energy boron implants using xR LEAP and RTP Centura XE/sub plus/: ramp rate effects up to 150/spl deg/C/sec
Document Type
Conference
Source
1998 International Conference on Ion Implantation Technology. Proceedings (Cat. No.98EX144) Ion implantation technology Ion Implantation Technology Proceedings, 1998 International Conference on. 2:732-735 vol.2 1998
Subject
Fields, Waves and Electromagnetics
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Boron
Implants
Rapid thermal annealing
Foundries
Nitrogen
Atmosphere
Temperature dependence
Temperature control
Crystallization
Electrons
Language
Abstract
In order to form junctions shallower than 0.1 /spl mu/m required for the source/drain extensions for 0.18 /spl mu/m technology and beyond, boron ions have been implanted in pre-amorphised Si at 1 keV and doses of 1E14-1E15 cm/sup -2/ using an Applied Materials xR LEAP ion implanter. Implanted wafers were subsequently annealed in an RTP Centura to /spl sim/1 sec soak time and to temperatures between 1000-1100/spl deg/C. Ramp up rates between 75/spl deg/C/s and 150/spl deg/C/s were examined. Junctions with depths between 40-80 nm (taken at 1E17 cm/sup -3/ SIMS B concentration) can be formed routinely with sheet resistance tuneable between 300-900 /spl Omega///spl square/ using Ge pre-amorphisation, and subsequent spike annealing at ramp up rates of 150/spl deg/C/sec in nitrogen atmosphere. It was found that sheet resistance (Rs) is most dependent on the spike anneal temperature, while the ramp up rate appear to have a minimal effect on reducing Rs or controlling junction depth (/spl chi//sub j/). The oxygen content in the RTA ambient is an important parameter in controlling both Rs and /spl chi//sub j/. The crystallinity of the spike annealed wafers has been evaluated using high resolution transmission electron microscopy (HRTEM).