The present disclosure is generally directed to semiconductor structures and methods that improve breakdown characteristics in finFET device designs, while retaining cost effectiveness for integration into the process flow. The semiconductor structure includes an extended lightly-doped-drain (LDD) region formed on a source/drain structure. The extended LDD regions provide extra separation between source and drain regions, which in turn provides for an increased source to drain resistance. The increased source to drain resistance improves the breakdown voltage of the semiconductor device, and significantly reduces its susceptibility to latch-up. The source to drain resistance may be tuned by adjusting the length of epi block regions, and may also be tuned by selecting desired doping profiles for the LDD and source/drain regions. The length of epi block regions may also be adjusted to maintain high uniformity of epitaxial growth in the S/D regions.