  We present a method for relieving aluminum 3D transmon qubits from a silicon
substrate using micromachining. Our technique is a high yield, one-step deep
reactive ion etch that requires no additional fabrication processes, and
results in the suspension of the junction area and edges of the aluminum film.
The drastic change in the device geometry affects both the dielectric and flux
noise environment experienced by the qubit. In particular, the participation
ratios of various dielectric interfaces are significantly modified, and
suspended qubits exhibited longer $T_1$'s than non-suspended ones. We also find
that suspension increases the flux noise experienced by tunable SQUID-based
qubits.
