Measurement of phosphorus segregation in silicon at the atomic-scale using STM

Abstract

In order to fabricate precise atomic-scale devices in silicon using a combination of scanning tunnelling microscopy (STM) and molecular beam epitaxy it is necessary to minimize the segregation/diffusion of dopant atoms during silicon encapsulation. We characterize the surface segregation/diffusion of phosphorus atoms from a $\delta$-doped layer in silicon after encapsulation at 250${}^{\circ }$C and room temperature using secondary ion mass spectrometry (SIMS), Auger electron spectroscopy (AES), and STM. We show that the surface phosphorus density can be reduced to a few percent of the initial $\delta$-doped density if the phosphorus atoms are encapsulated with 5 or 10 monolayers of epitaxial silicon at room temperature. We highlight the limitations of SIMS and AES to determine phosphorus segregation at the atomic-scale and the advantage of using STM directly.

References in corpus (2)

• Towards the fabrication of phosphorus qubits for a silicon quantum computer
• Encapsulation of phosphorus dopants in silicon for the fabrication of a quantum computer

Cited by in corpus (7)

• Multivalley effective mass theory simulation of donors in silicon
• Addressable electron spin resonance using donors and donor molecules in silicon
• The impact of stochastic incorporation on atomic-precision Si:P arrays
• Atomic Precision Advanced Manufacturing for Digital Electronics
• Probing the Atomic Arrangement of Sub-Surface Dopants in a Silicon Quantum Device Platform
• Direct integration of atomic precision advanced manufacturing into middle-of-line silicon fabrication
• Quantifying Atom-scale Dopant Movement and Electrical Activation in Si:P Monolayers