S

OMEBIPOLARDEVICEPROBLEMS,
ANDPOTENTIALCAUSES

Problem

Potential Causes

Other Device Characteristics

Affected

Confirmation

Comments

Low Beta

Basetoodeep
Basetooheavily doped Emittertooshallow Emittertoolightly doped

C.S.,

C.S.,

S.R.P.

S.R.P.

BaseRs

EmitterRs

Excess RecombinationHighVCE offset
Sites (EG,GOLD)
Surfaceleakage
(Ingeneral,toomuchrecombination withinbase)

Basetooshallow
Basetoolightly dopedBaseRs
Emittertoodeep
Emittertooheavily dopedEmitterRs
Buriedlayer incontactBVcbo(with& withoutburied layer)
withbase (outdiffusion)
(ingeneral, baseunder emitter is too thin)

HighBeta

C.S.,

C.S.,

C.S.

S.R.P.

S.R.P.