S

OMEBIPOLARDEVICEPROBLEMS,

ANDPOTENTIALCAUSES

Problem

PotentialCauses

Other DeviceCharacteristics Affected

Confirmation Comments

LowBVceo

(1) LowBVcbo:
*Heavily dopedEPIBVcbo, BVsco
*Large buried layerBVcbo(with and
Outdiffusionwithout B.L.)
*Thin EPIBVcbo(with and
Without B.L.)
*Deep BaseBVcbo(with and
without B.L.) Beta (2)High Beta (see above)High beta
(3)Emitter-collector spikeExcess leakage E-C; lowearly V. (in general, EPI effectively too thin underbase, aboveB.L.)

S.R.P.
C.S..S.R.P.

C.S.

C.S.

LowEarly(1)High betaHigh beta Voltage(2)Emitter-collector spikeExcess leakage E-C (SlopedI vs V)(3)Emitter-collector pipeExcess leakage E-C
(In general, large change in base depletion with VCE)

(Wright Etch?) (Wright Etch?)