Ferroelectric properties of II-VI type wide gap semiconducting thin films on Si(100)

We demonstrate that non-oxide (II-VI type semiconductors) ferroelectric thi n films on Si(100), such as (Zn,Cd)Te, (Zn,Cd)Se and (Zn,Cd)S, have ferroel ectric properties. Furthermore, thin films of (LixZn1-x)O, which is also a II-VI type semiconductor, display ferroelectric hysteretic features with me mory windows of between 0.2 V and 0.5 V corresponding to the value of x. Th e material design for producing the ferroelectric nature is done by replaci ng some of the host atoms with other smaller atoms. The substituted atoms c an occupy off-center positions, thus locally inducing electric dipoles, the reby leading to ferroelectric behavior. These II-VI wide gap semiconducting ferroelectric films will open the door to new memory devices.