  We demonstrate post-fabrication target-wavelength trimming with a gallium
phosphide on silicon nitride integrated photonic platform using controlled
electron-beam exposure of hydrogen silsesquioxane cladding. A linear
relationship between the electron-beam exposure dose and resonant wavelength
red-shift enables deterministic, individual trimming of multiple devices on the
same chip to within 30 pm of a single target wavelength. Second harmonic
generation from telecom to near infrared at a target wavelength is shown in
multiple devices with quality factors on the order of $10^4$. Post-fabrication
tuning is an essential tool for targeted wavelength applications including
quantum frequency conversion
