  Superconducting quantum processors are one of the leading platforms for
realizing scalable fault-tolerant quantum computation (FTQC). The recent
demonstration of post-fabrication tuning of Josephson junctions using
alternating-bias assisted annealing (ABAA) technique and a reduction in
junction loss after ABAA illuminates a promising path towards precision tuning
of qubit frequency while maintaining high coherence. Here, we demonstrate
precision tuning of the maximum $|0\rangle\rightarrow |1\rangle$ transition
frequency ($f_{01}^{\rm max}$) of tunable transmon qubits by performing ABAA at
room temperature using commercially available test equipment. We characterize
the impact of junction relaxation and aging on resistance spread after tuning,
and demonstrate a frequency equivalent tuning precision of 7.7 MHz ($0.17\%$)
based on targeted resistance tuning on hundreds of qubits, with a resistance
tuning range up to $18.5\%$. Cryogenic measurements on tuned and untuned qubits
show evidence of improved coherence after ABAA with no significant impact on
tunability. Despite a small global offset, we show an empirical $f_{01}^{\rm
max}$ tuning precision of 18.4 MHz by tuning a set of multi-qubit processors
targeting their designed Hamiltonians. We experimentally characterize
high-fidelity parametric resonance iSWAP gates on two ABAA-tuned 9-qubit
processors with fidelity as high as $99.51\pm 0.20\%$. On the best-performing
device, we measured across the device a median fidelity of $99.22\%$ and an
average fidelity of $99.13\pm 0.12 \%$. Yield modeling analysis predicts high
detuning-edge-yield using ABAA beyond the 1000-qubit scale. These results
demonstrate the cutting-edge capability of frequency targeting using ABAA and
open up a new avenue to systematically improving Hamiltonian targeting and
optimization for scaling high-performance superconducting quantum processors.
