Dislocation sink annihilating threading dislocations in strain-relaxed Si1-xGex layer

초록

We proposed a dislocation sink technology for achieving Si1-xGex multi-bridge-channel field-effect-transistor beyond 5 nm transistor design-rule that essentially needs an almost crystalline-defect-free Si1-xGex channel. A generation of a dislocation sink via H+ implantations in a strain-relaxed Si0.7Ge0.3 layer grown on a Si substrate and a following annealing almost annihilate completely misfit and threading dislocations located near the interface between a relaxed Si0.7Ge0.3 layer and a Si substrate. A real-time (continuous heating from room temperature to 600 degrees C) in situ high-resolution-transmission-electron-microscopy and inverse-fast-Fourier-transform image observation at 1.25 MV acceleration voltage obviously demonstrated the annihilation process between dislocation sinks and remaining misfit and threading dislocations during a thermal annealing, called the [Si-I or Ge-I +V-Si or V-Ge -> Si1-xGex] annihilation process, where Si-I, Ge-I, V-Si, and V-Ge are interstitial Si, interstitial Ge, Si vacancy, and Ge vacancy, respectively. In particular, the annihilation process efficiency greatly depended on the dose of H+ implantation and annealing temperature; i.e. a maximum annihilation process efficiency achieved at 5 x 10(15) atoms cm(-2) and 800 degrees C.

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