Reduction of lateral parasitic current flow by buried recombination layers formed by high energy implantation of C or O into silicon

Buried recombination layers were formed in silicon by high energy implantation of carbon or oxygen and subsequent annealing. The parasitic lateral bipolar transistors in latch-up test structures with these buried recombination layers showed a strong decrease of the current gain by 2 to 3 orders of magnitude in n-type silicon and by 4-5 decades in p-type silicon. Reduction of lateral minority carrier diffusion was tested by injecting minority carriers in the vicinity of a reverse biased well recording the resulting reverse currents. The distance between well and injecting contact was varied between 10 and 50 μm. The carbon implanted layer reduced the reverse current by up to 6 orders of magnitude while the oxygen implanted layer reduced the current by up to 3 orders of magnitude