  Defects in silicon carbide have been explored as promising spin systems in
quantum technologies. However, for practical quantum metrology and quantum
communication, it is critical to achieve the on-demand shallow spin-defect
generation. In this work, we present the generation and characterization of
shallow silicon vacancies in silicon carbide by using different implanted ions
and annealing conditions. The conversion efficiency of silicon vacancy of
helium ions is shown to be higher than that by carbon and hydrogen ions in a
wide implanted fluence range. Furthermore, after optimizing annealing
conditions, the conversion efficiency can be increased more than 2 times. Due
to the high density of the generated ensemble defects, the sensitivity to sense
a static magnetic field can be research as high as , which is about 15 times
higher than previous results. By carefully optimizing implanted conditions, we
further show that a single silicon vacancy array can be generated with about 80
% conversion efficiency, which reaches the highest conversion yield in solid
state systems. The results pave the way for using on-demand generated shallow
silicon vacancy for quantum information processing and quantum photonics.
