ESR From boron in silicon at zero and small external stress I. Line positions and line structure

ESR observations at zero external stress of the shallow acceptor centre boron in silicon are reported for the first time. These observations have become possible by the high degree of crystal perfection attainable today in Si‐crystal growth. The spectrum, its angular and uniaxial pressure dependence are interpreted in terms of a spin Hamiltonian given by Bir. Additional terms in this spin Hamiltonian are shown to be necessary to account for the experimental result and to explain the differences between the spin Hamiltonian constants derived by different authors.