臺灣博碩士論文加值系統

具有50A的空間層和於基-射極異質接面加一單原子摻雜層之磷化銦鎵/砷
化鎵單異質接面雙極性電晶體已被成功製造並加以探討.從理論的分析與
實驗的結果可以發現,由於50A的背置空間層和單原子摻雜層,確實可有效
地消除N-磷化銦鎵/砷化鎵異質接面間的位障尖峰.而共射極之電流增益可
達280且集-射極補償電壓也可小至55mV.此外,在低集極電流如0.5uA,且沒
有在基-射極加以保護層及射極薄化的技巧之下,仍可獲得高電流增益與低
補償電壓,這也證明位障尖峰確實由於單原子摻雜層的使用而被消除.總而
言之,我們使用了一種新的方法來去除位障尖峰.而在此同時,亦可維持在
低集極電流區的高電流增益.藉著使用一單原子摻雜層於基-射極異質接
面,電子的障位,即位障尖峰已被降低,傳導穿越異質接面的熱場穿透電子
數目也減少,因此,電洞的侷限效應與射極注入效率也因此增進許多.再者,
射-基接面的導通電壓及集極電流的理想因子均可被降低,這些都可促成低
集-射極補償電壓及高電流增益的優良特性.

An InGaP/GaAs single heterojunction bipolar transistor (SHBT)
with an 50A setback layer and a d-doped sheet inserting between
base-emitterheterointerface was fabricated successfully and
stuided. From the theoreticalanalysis and experimental results,
it is found that the insertion of a 50Asetback layer and a d-
doped sheet can effectively eliminate the undesiredpotential-
spike at N-InGaP/GaAs heterojunction. A common-emitter current
of280 and an offset voltage as small as 55mV are obtained. In
addition, a currentgain of 11 is obtained at a very small
collector current of 0.5uA withoutthe passivation and emitter-
thinning techniques of base-emitter junction.These results
indicate that the high current gain and low offset voltage can
be obtained without the passivation of emitter-base junction. It
shows the evidencethat the potential spike is indeed reduced by
the employment of a d-doped sheet.In summary, we employ a new
method to effectively supress the potential spikewhile a high
current gain, especially at low collector current is maintained,
simultaneously. By using a d-doped sheet at the emitter-base (E-
B) heterojunction,the electron barrier, potential spike, is
reduced while the effecitive hole barrier is increased. Due to
the reduction of potential spike, the thermionic-fieldtunneling
of electrons transport across the heterojunction is decreased.
Thus,the hole confinement effect and emitter injection
efficiency may be enhanced. Furthermore,the B-E junction turn-on
voltage and the ideality factor of collector currentare reduced.
It implies that a low collector-emitter offset voltage(dVce) and
high current-gain can be obtained.