| 摘要 |
Semiconductor devices are known comprising a multiple p-n junction RESURF semiconductor material (10) that provides a voltage-sustaining space-charge zone when depleted from a blocking junction (40). Charge balance is important in the alternating p-type (11) and n-type (12) regions which together provide the voltage-sustaining space-charge zone. The invention provides a low-cost yet reliable way of manufacturing such a material (10), and also devices with such a material (10). A p-type silicon body (100) having an acceptor doping concentration (Na) for the p-type regions (11) of the material is subjected to irradiation with collimated beams (152) of thermal neutrons (150) at window areas (52) in a mask (50) so as to form the n-type regions (12) by transmutation of silicon atoms into phosphorus. A well-defined and controllable phosphorus doping concentration to balance the low acceptor concentration of the p-type regions (11) is achievable in this manner, even when the acceptor concentration is of boron. The silicon body (10) so formed with the alternating p-type and n-type regions (11,12) is sliced and/or polished transverse (110) to the p-n junctions (21) between the p-type and n-type regions (11,12) so as to form a wafer for device manufacture. The invention is particularly advantageous for the manufacture of high voltage MOSFETs having a low on-resistance.
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