Embodiments of microelectronic assemblies are provided. First and second semiconductor devices are formed over a substrate having a first dopant type at a first concentration. First and second buried regions having a second dopant type are formed respectively below the first and second semiconductor devices with a gap therebetween. At least one well region is formed over the substrate and between the first and second semiconductor devices. A barrier region having the first dopant type at a second concentration is formed between and adjacent to the first and second buried regions such that at least a portion of the barrier region extends a depth from the first and second semiconductor devices that is greater or equal to the depth of the buried regions.