The unit and the surname share a writing because the curie was named after Marie Curie (
玛丽·
居里, Marie Curie, 1867–1934) and Pierre Curie (
皮埃尔·
居里).
居 (jū) and
里 (lǐ) here are pure phonetic transliteration ('cu-rie'), but they happen to mean 'reside / inside-the-village' in Chinese — sometimes mis-parsed by learners as a regular compound.