Electrodeposition as an Alternative Approach for Monolithic Integration of InSb on Silicon

Abstract

High-performance electronics would greatly benefit from a versatile III-V integration process on silicon. Unfortunately, integration using hetero epitaxy is hampered by polarity, lattice, and thermal expansion mismatch. This work proposes an alternative concept of III-V integration combining advantages of pulse electrodeposition, template-assisted selective epitaxy, and recrystallization from a melt. Efficient electrodeposition of nano-crystalline and stochiometric InSb in planar templates on Si (001) is achieved. The InSb deposits are analysed by high resolution scanning transmission electron microscopy (HR-STEM) and energy-dispersive X-ray spectroscopy (EDX) before and after melting and recrystallization. The results show that InSb can crystallise epitaxially on Si with the formation of stacking faults. Furthermore, X-ray photoelectron (XPS) and Auger electron (AE) spectroscopy analysis indicate that the InSb crystal size is limited by the impurity concentration resulting from the electrodeposition process.

Selective electrodeposition of indium microstructures on silicon and their conversion into InAs and InSb semiconductors

“…2 b). This contrasts with our previous results [ 6 ] of conformal filling with amorphous and nanocrystalline InSb deposits.

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“…Interestingly, the InSb appears to be in contact with the Si surface. However, there is no epitaxial relationship between the Si and the InSb, and the expected dissolution or etching at the Si interface as previously reported for InSb-Si system [ 6 ] by the InSb melt was not observed. Both findings suggest that an unintentional contamination of interface was introduced during the saturation process, suppressing the formation of a heteroepitaxial InSb-Si interface.…”

“…During our previous research, direct pulse-electrosynthesis of InSb on silicon was developed and similarly significant amounts of carbon and oxygen impurities were observed. The main source of contaminations was by-products from the decomposition of the complexing agents (citric acid and sodium citrate) [ 6 ], suggesting that using multicomponent electrolytes might not be the optimum approach for In and In-based semiconductors synthesis. A high purity In deposit is particularly important if it is used as starting material for In- group-V semiconductors.…”

“…metal–organic chemical vapour deposition, MOCVD) methods. It is well known that wet techniques allow to fill different shapes of templates in a short period of time [ 6 ]. That means, that even very complicated, nano- or microscale templates can be filled uniformly resulting in an ideal platform for V-element saturation.…”

“…Detailed investigation of gold, copper and platinum deposition mechanisms on silicon can be found in Oskam et al [1]. Direct electrodeposition of gold [2], copper oxide [3], zinc oxide [4], GaN [5] and recently InSb [6,7] on Si were shown but are often limited by low adhesion, compatibility issues such as the need for conductive substrates, and non-intentional impurities in the deposits. To resolve the above challenges, careful selection of the electrodeposition process, electrolyte composition and substrate preparation must be made.…”