Infrared-Activated Selective Etching of P+ Silicon for Failure Analysis
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
A reliable failure analysis technique is reported that combines infrared (IR) radiation with a silicon wet etch to delineate P+/Nboundaries for ion-implanted or diffusion dopant concentration related defects. Because of small size, turn-around time and complex processing conditions, visual inspection of DRAMs and dense logic chips requires appropriate physical diagnostic tools and techniques for fast detection of problems. An IR/wet etch technique, which can replace the silicon "dash etch" failure analysis method, affords better control when applied to 12 ohm-cm  P substrate wafers.