  Holes in silicon quantum dots are receiving significant attention due to
their potential as fast, tunable, and scalable qubits in semiconductor quantum
circuits. Despite this, challenges remain in this material system including
difficulties using charge sensing to determine the number of holes in a quantum
dot, and in controlling the coupling between adjacent quantum dots. In this
work, we address these problems by fabricating an ambipolar complementary
metal-oxide-semiconductor (CMOS) device using multilayer palladium gates. The
device consists of an electron charge sensor adjacent to a hole double quantum
dot. We demonstrate control of the spin state via electric dipole spin
resonance (EDSR). We achieve smooth control of the inter-dot coupling rate over
two orders of magnitude and use the charge sensor to perform spin-to-charge
conversion to measure the hole singlet-triplet relaxation time of 11 {\mu}s for
a known hole occupation. These results provide a path towards improving the
quality and controllability of hole spin-qubits.
