The Formation and Structure of Thermomigration Silicon Channels Doped with Ga

Abstract

Vertical through Si(Ga) p channels are created at 1450 K in c-Si(111) plates by thermomigration of local gallium zones. To this end, a technique is proposed and implemented for the formation of local zones consisting in the filling of linear grooves with a of width 60−100 μm and depth of 30−50 μm etched in the silicon plate with a fine-grained Ga powder. It is shown that a high yield of acceptable zones occurs with powder grains with a size of 5 μm and at ∼284 K. The obtained thermomigration Si(Ga) p channels are studied by the X-ray methods of double-crystal diffraction reflection curves and projection topography. The structural perfection of gallium p channels is characterized based on their comparison with features of the structure of thermomigration Si(Al) channels, obtained close to retrograde temperature 1380 K. It is shown that dislocation half-loops pinned at their ends at the boundaries of both thermomigration channels are a typical form of structural defects at their boundaries. The magnitudes of deformation of (2−5) × 10–5 and bending of 15″−30″ of the crystal planes close to the channel–matrix of the plate interface of the samples under study are determined. In the Vegard model, the concentration of aluminum and gallium atoms implanted into a crystal lattice of the silicon channels of the samples was CAl ∼ 1019 cm−3 and CGa ∼ 1.9 × 1019 cm−3, respectively.