Browse Prior Art Database

Ion Implanted Emitters

IP.com Disclosure Number: IPCOM000082990D
Original Publication Date: 1975-Mar-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 90K

Publishing Venue

IBM

Related People

Feng, BC: AUTHOR [+2]

Abstract

One problem with ion implanted emitters is the recession of thermal oxide SiO(2)4 underneath the Si(3)N(4) window 6 to emitter 8, as shown in Fig. 1.

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Ion Implanted Emitters

One problem with ion implanted emitters is the recession of thermal oxide SiO(2)4 underneath the Si(3)N(4) window 6 to emitter 8, as shown in Fig. 1.

One solution to the ion implanted emitter thermal oxide recession problem is to deposit oxynitride (SiON) or Si(3)N(4) 10 and pyrolytic oxide 12 after base drive-in, as shown in Fig. 2. Oxynitride minimizes stress.

The oxynitride or Si(3)N(4)is etched in hot reflux phosphoric acid, with pyrolytic oxide as a mask, as shown in Fig. 2. A block mask opens the emitter and N+ contacts. The P and SBD contacts are covered with a photo-resist or optical process 14 as shown in Figs. 3 and 4. After photoresist is stripped, Si(3)N(4) or SiON is again etched in hot phosphoric acid and a thin step of base oxide 16 approximately 800 Angstroms is formed, as shown in Fig. 5. By masking again the P and SBD contacts with photoresist, a shallow N+ emitter 18 is implanted in the exposed silicon window and underneath the thin base oxide as shown in Fig. 6, which eliminates the risk of exposing the P- base 20 and N+ emitter 18 in the emitter window to metallization.

Another solution is to open the contact window (see Fig. 3) and apply another photoresist 22 having a larger window. Adding another photoresist produces the junction profile shown in Fig. 7.

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