Low Resistance Reach Through to a Buried Collector
Original Publication Date: 1978-Jun-01
Included in the Prior Art Database: 2005-Feb-21
A process for forming a bipolar transistor structure which achieves low collector series resistance and metal gettering of active device regions is as follows: 1) Standard processing is used to form buried collector region 2 in silicon body 3. 2) Strip the SiO(2) mask. 3) Use resist material to mask the part of the collector region where the active device will ultimately be. The window region will be the collector contact or reach-through region. 4) Ion implant phosphorous or another donor impurity with the correct energy and dosage so that the silicon surface is heavily damaged. It may be desirable to implant the ions through a screen of silicon dioxide to obtain oxygen knock-ons since such implanted damage does not easily anneal. The resulting region is 4. 5) Deposit epitaxial silicon layer 5.