離子佈植矽單晶之退火奈米雙晶組織研究
Date Issued
2005
Date
2005
Author(s)
徐偉倫
DOI
zh-TW
Abstract
Ion implantation is the most popular method for doping the silicon wafer in recent semiconductor industry. Following the recent trend of miniaturization of microelectronic devices, microstructure analysis of thin film recrystallized, ion implanted silicon becomes more and more important. Previous research work has indicated that planar defects such as stacking faults, twins, and lamellar nano-twins will formed in ion implanted silicon thin film during annealing. It is known that twin boundaries significantly affect electrical properties of thin films. However, a fundamental knowledge of lamellar nano-twins is not yet been understood.
In this work, more attention has been paid to the nano-twins and the evolution of solid phase epitaxial regrowth in the annealed specimens. Using field emission gun transmission electron microscope, we make microstructure observations upon different annealing cases, which include different annealing time and different implantation energy, to elucidate the micro structural development.
Two implantation energies used on p-type silicon wafers are 150KeV and 200KeV, respectively. The dose is 1×1016 Ar+/㎝2 for both cases, and annealing temperature is 800℃. After TEM examination, it is evident that stacking faults and lamellar nano-twins did formed on {111} of ion implanted silicon during annealing. As annealing time increases from 10 min to 1 hr, the solid phase epitaxial regrowth (SPER) front moves from the previous crystalline/amorphous interface, 270 nm and 340 nm in each case, toward specimen surface. SPER front stopped at certain depths for annealing time between 1hr and 4hr, and there were no further movements for annealing time 4hr and 8hr, the SPER front stopped at depth of 160 nm and 220 nm in each case. Different ion concentration distribution along implant direction has a great impact on the subsequent annealing treatment. Higher implantation energy retards the process of recrystallization at the initial stage of annealing (i.e. 10 min @800℃); the corresponding TEM reveals that some amorphous areas still exist.
Subjects
離子佈植
矽單晶
奈米
雙晶
退火
Ion implantation
silicon
nano
twin
annealing
Type
thesis