A laterally diffused metal oxide silicon (LDMOS) transistor and a method of making the LDMOS transistor are disclosed. The LDMOS transistor includes a drain drift region formed in a substrate and containing a drain contact region. A gate structure overlies a channel region in the substrate and a first shallow-trench isolation (STI) structure located between the drain contact region and the channel region. The first STI structure contains a high-k dielectric and a second STI structure contains silicon oxide.