The disclosed technology relates generally to semiconductor devices, and more particularly to semiconductor devices such as field-effect transistor devices configured for biomolecule sensing. In one aspect, a semiconductor chip comprises at least one field-effect transistor device which comprises a source, a drain, a gate stack and a channel region formed between the source and the drain. The gate stack only partially overlaps the channel region at the source side and/or at the drain side, such that a non-overlapped channel region at the source side and/or at the drain side is formed, where the non-overlapped channel region is configured for sensing biomolecules.