A supernova may actually be necessary in the creation of a stellar black hole.
At the ends of their lives the cores of massive stars are made mostly of iron-peak nuclei from which you cannot extract more fusion energy. To support their weight, these stars rely on electron degeneracy pressure - the pressure caused by the Pauli exclusion principle allowing no more than one electron to share the same quantum state.
In principle a star might be supported by degeneracy pressure forever as it gradually cools - this is the fate of most white dwarfs.
However, the core of a massive star is just too big for that to work. The density increases until all the electron are moving at close-to the speed of light and that's as high as the degeneracy pressure can get. If the core exceeds the Chandrasekhar mass, it will collapse and as it does so, the rest of the star collapses with it (a little more slowly).
The collapse is triggered by the removal of electrons by electron capture into nuclei to form neutrons. At some point enough neutrons are produced for neutron degeneracy pressure to halt or at least slow the collapse. This and the release of a lot of gravitational potential energy are ultimately what power a supernova explosion. But if the collapse is not halted then even neutron degeneracy pressure will not support the star and collapse to a black hole becomes inevitable. A black hole status is reached once a proportion of its mass is compressed inside its Schwarzschild radius $r_s = 2GM/c^2$. i.e. once its density achieves
$$ \rho > \frac{3M}{4\pi r_s^{3}}$$
i.e. when a central mass $M$ has a density that exceeds
$$ \rho > \frac{3}{32\pi} \frac{c^6}{G^3 M^2} = 1.8\times10^{19} \left(\frac{M}{M_{\odot}}\right)^{-2}\ {\rm kg/m}^3$$
This is a ball park figure and assumes spherical symmetry and neglects any detailed GR treatment, but is more or less correct - a few times higher than typical neutron star densities.
In other words it is the density of the material that largely determines whether something becomes a black hole. The mass is only an indirect parameter.