A NEW PLANAR-STRUCTURE INALGAAS-INALAS SUPERLATTICE AVALANCHE PHOTODIODE WITH A TI-IMPLANTED GUARD-RING

High-speed quasi-planar-structure InAlGaAs-InAlAs superlattice avalanc he photodiodes (SL-APD's) have been fabricated with a newly proposed T i-implanted guard-ring. The APD's exhibited a uniform multiplication p rofile at a multiplication factor of 50 with no edge-multiplication. T he dark current was 2.2 mu A at a multiplication factor of 10. High-sp eed response characteristics were confirmed with a gain-bandwidth prod uct of 110 GHz and a high cut-off frequency of 15 GHz, even at a low m ultiplication factor of 1.5, These characteristics are the first demon stration of planar-structure SL-APD's for 10 Gb/s optical receivers us e.