Dislocation behavior in heavily germanium-doped silicon crystal

Eliminating Light-Induced Degradation in Commercial p-Type Czochralski Silicon Solar Cells

“…In the case of germanium doping, the doping is believed to enhance the diffusivity barrier for O i , or form Ge-O complexes, therefore reducing the availability of interstitial oxygen species to form B-O defects [65]. However, the required germanium doping in the order of 1 × 10 20 cm −3 to prevent LID is probably not desirable for industrial-scale production due to the increased ingot growth costs and tendency to induce the nucleation of multi-crystalline silicon growth [65,66]. For carbon co-doping, carbon is believed to compete with boron for the formation of complexes with oxygen [67].…”

Constitutional supercooling in heavily As-doped Czochralski Si crystal growth

“…Generally, in heavily doped crystal growth, when the impurity concentration increases before reaching the maximum solid solubility, cellular growth due to constitutional supercooling occurs and this finally leads to a polycrystalline structure. In the case of Si, constitutional supercooling in CZ crystal growth heavily doped with Sb [4], B [5] and Ge [6] has been reported. The discrimination of constitutional supercooling has been theoretically proposed as follows [7]:…”

“…Constitutional supercooling occurs readily when the segregation coefficient is small and the growth rate is large. Indeed, the equilibrium segregation coefficients of Sb, B and Ge are 0.023 [8], 0.8 [8] and 0.5 [6], respectively. In the case of B, k 0 has been found to decrease with increasing B concentration in the melt, to the value 0.38 when constitutional supercooling occurs [5].…”

“…The concentrations of B and Ge in Si crystals grown at a pulling rate of approximately 1mm/min when constitutional supercooling occurs were reported to be 2.8×10 20 [5] and, 5.7×10 20 cm -3 [6], respectively. Such concentrations are lower than the maximum solid solubilities of each impurity.…”

Characterization of a Czochralski grown silicon crystal doped with 1020 cm‐3 germanium

“…Moreover, it has been reported that flow pattern defects (FPDs) can be reduced in GCZ Si [9]. Furthermore, Ge doping can also increase the mechanical strength by slowing down dislocation movement [10,11]. However, the effects of larger concentrations of Ge doping on CZ silicon are not clear, especially when the concentration of Ge goes up to 10 20 cm -3…”