Redistribution and precipitation of dopant on thermal annealing of bismuth implanted silicon

Journal Article · Sat Jan 01 00:00:00 EST 1983 · Proc. - Annu. Meet., Electron Microsc. Soc. Am.; (United States)

OSTI ID:6368172

Pennycook, S J; Narayan, J; Holland, O W

Ion implantation above a certain dose leads to the formation of amorphous layers, which if recrystallized under interface-controlled growth at 450-600/sup 0/C, result in solid solutions far exceeding the equilibrium solubility limits. Annealed high-dose implanted specimens were studied at 1000/sup 0/C for one hour to determine the redistribution and precipitation of dopant due to the presence of extended defects. A cross section TEM image taken near the (011) Si pole of (100)Si implanted with /sup 209/Bi/sup +/ (250 KeV, 5 x 10/sup 15/ cm/sup -2/) and annealed (1000/sup 0/C, 1 hr) is shown. As well as a band of precipitates typically 5 nm in size centered at a depth of 100 nm there are some much larger precipitates (28 nm in size) at the original surface of the silicon. These show a curved meniscus protruding out of the surface since the bismuth is liquid at the annealing temperature. These precipitates are located on twins suggesting that the dopant had diffused along the twin boundaries from the band of high concentration to the surface. Those precipitates in the underlying band which lie on dislocations are also selectively coarsened. Twin boundaries and dislocations act as fast diffusion paths leading to the redistribution of dopant.

• Research Organization: Oak Ridge National Lab., TN
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6368172
• Journal Information: Proc. - Annu. Meet., Electron Microsc. Soc. Am.; (United States), Vol. 41
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SILICON
ANNEALING
ION IMPLANTATION
BISMUTH IONS
CRYSTALLIZATION
DOPED MATERIALS
PHYSICAL RADIATION EFFECTS
PRECIPITATION
TRANSMISSION ELECTRON MICROSCOPY
CHARGED PARTICLES
ELECTRON MICROSCOPY
ELEMENTS
HEAT TREATMENTS
IONS
MATERIALS
MICROSCOPY
PHASE TRANSFORMATIONS
RADIATION EFFECTS
SEMIMETALS
SEPARATION PROCESSES
360106* - Metals & Alloys- Radiation Effects