US 7,320,895 B1
Thyristor-based device having dual control ports
Andrew Horch, Sunnyvale, Calif. (US); Scott Robins, San Jose, Calif. (US); and Farid Nemati, Menlo Park, Calif. (US)
Assigned to T-Ram Semiconductor, Inc., Milpitas, Calif. (US)
Filed on Mar. 22, 2005, as Appl. No. 11/86,113.
Application 11/086113 is a division of application No. 10/288953, filed on Nov. 06, 2002, granted, now 6,965,129.
Int. Cl. H01L 21/00 (2006.01); H01L 21/332 (2006.01)
U.S. Cl. 438—5  [438/138; 257/E21.529] 9 Claims
OG exemplary drawing
 
1. A method for manufacturing a semiconductor device having adjacent thyristor body regions in a substrate, the thyristor body regions being oppositely doped and having a junction therebetween, the method comprising:
etching a trench in a substrate;
lining the trench with an insulative material;
forming conductive material in the trench, separated from a first one of the thyristor body regions by the insulative material and extending above the junction;
etching a portion of the semiconductor device including the conductive material in the trench; and
detecting a characteristic of the material being etched and controlling the etching as a function of the detected characteristic;
wherein detecting a characteristic of the material being etched includes detecting that the conductive material has been etched to a depth that is aligned with the junction.