A device includes integrated circuit chips mounted on one another. At least one component for protecting elements of a second chip is formed in a first chip. The chips may be of the SOI type, with the first chip including a first SOI layer having a first thickness and the second chip including a second SOI layer having a second thickness smaller than the first thickness. The first chip including the component for protecting may include an optical waveguide with the component for protecting formed adjacent the optical waveguide.