Quantitative investigation of SiGeC layers using atom probe tomography

99.992% 28Si CVD-grown epilayer on 300 mm substrates for large scale integration of silicon spin qubits

“…and if a higher level of isotopic purification is needed. In bulk 28 Si ( 29 Si=0.005 % ), very long T 2 for electron spins on phosphorus donors at a concentration of 1.2 10 14 cm −3 has been measured by electron spin resonance techniques: T 2 =600 ms, extrapolated to 10s by using a magnetic field gradient impeding flip-flop relaxation with residual nuclear 29 Si spins 8 . The fundamental limit is T 2 T 1 =2000s at low temperature, indicating that progress can still be made if one reduces the 29 Si content beyond 0.08% in the silicon crystal used to date for spin quantum bits 8 .…”

“…The general objective of the presented study is to obtain 28 Si crystalline layers with enrichment ≥99,992 % and a very low level of other contaminants to fulfill the strict requirements of pre-industrial CMOS foundries. A first CMOS qubit fabricated in a pre-industrial foundry has been recently published by some of us 9 .…”

“…For instance the content of P and B dopants should be 10 12 cm −3 or less, C and O contents 10 15 cm −3 or less. The high morphological quality 28 Si epilayers should be grown on 300 mm natural abundance Si substrates or silicon-oninsulator (SOI) substrates. The supply chain should also provide enough isotopically purified materials to grow dozens of 300 mm diameter epilayers.…”

Quantification of dopant species using atom probe tomography for semiconductor application

“…CSR is an index of field strength where a high CSR value indicates an elevated electric field and vice versa. The use of this ratio gives a simple indication of the field strength and allows reproducible conditions to be used from one sample to another . The relationship between the Si CSR and the ratio of different complex ions of phosphorus is shown in Figure .…”

“…The use of this ratio gives a simple indication of the field strength and allows reproducible conditions to be used from one sample to another. 5,21 The relationship between the Si CSR and the ratio of different complex ions of phosphorus is shown in Figure 6. In Figure 6, P1 consists of 59 SiP + and 15.5 P 2+ excluded peak at 31 Da.…”