In modern particle physics, elementary particles are indeed described as excitations of quantum fields. Each type of elementary particle is associated with its own unique quantum field. These fields are fundamental entities in the Standard Model of particle physics.
To clarify, it is not the case that there is one field with multiple excitations for different particles. Rather, there are multiple distinct quantum fields, each associated with a specific type of elementary particle. For example, there is an electron field, a photon field, a quark field, and so on.
These quantum fields pervade all of spacetime, and the particles themselves are understood as localized excitations or disturbances within these fields. When a quantum field is excited, it gives rise to a particle with certain properties such as mass, charge, and spin. The nature of the excitation determines the particle's characteristics.
In summary, elementary particles are considered excitations of distinct quantum fields. Each particle type corresponds to its own unique field, and the properties of the particles arise from the specific excitations within these fields.