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HBT technology is an indispensable part to provide high performance integrated circuit power amplifiers for both handsets and infrastructure. Extremely high linearity, low voltage operation, and high efficiency, along with low cost small size, with the simplicity of single polarity power supplies are among HBT’s many virtues. These attributes are absolutely essential for hand held wireless devices, and they are very hard to achieve with the older technologies such as Si bipolar or GaAs MESFET. [Message from a professional Industry Consultant]

	HBT	Si Bipolar or MESFET
Intermod Efficiency	15~20dB	8 dB(Si bipolar)
Supply biasing	3 to 5 volts	8 to 15 volts(Si bipolar or GaAs MESFET)

The biggest merit of InGaP over AlGaAs is greatly longer life time which is about 10 to 20 times of that of AlGaAs.

	AlGaAs HBT	InGaP HBT	Description
Life Time	1~2 years	More than 20 years	Difference by materials Oxidation problem in Al causes short life. Less Oxidation & Defect in InGaP
Etching Difference	Complicated Dry Etching	Simple Selective Wet Etching	Higher Yield from InGaP HBT Etching
Band Alignment	ΔEc=0.25eV, ΔEv=0.13	ΔEc=0.12eV, ΔEv=0.38	The higher DEv gets, The less dependency of current gain on the temperature. Dramatically low current gain when temperature goes high in AlGaAs.
The perfect spatial coincidence of p-n and hetero junc.	Ga-C bond (59 kcal/mol)	In-C bond (47 kcal/mol)	The practical concern during material growth. The presence of indium in InGaP inhibits carbon incorporation and eliminates memory effect associated with carbon sources.

Whereas ordinary foundries has one type of process for customers, Knowledge*ON has 3 kind of different processes which were designed to meet different type of customer’s applications:

1) High Power InGaP HBT process (for GSM, DCS, Base-station etc.)
    BVceo>20~23V, fT>34GHz, fmax>84GHz
    GSM PAM requires Higher Bvceo than other applications. We have High Power process
    which of HBT has Bvceo of more than 23V, compared with 13V of ordinary foundry.

2) High Linearity InGaP HBT process (for CDMA, WCDMA, WLAN etc.)
    BVceo>13V, fT>50GHz, fmax>80GHz
    High Linearity process we have that affects to ACPR of CDMA PA.

3) High Speed InGaP HBT process (for TIA, LD, Optical Comm. Systems,
    High speed digital circuits, WLAN etc.)
    BVceo>10V, fT>60GHz, fmax>105GHz

1. Low Rth
    Rth of Knowledge*ON’s HBT is 25% lower than that of other foundries, so we have reduced
    Tj extending device life time as well.

2. Accurate Model(Including Thermal Effect)
    We have VBIC model, which is more accurate than simple Gummel-Poon models that other
    foundries are offering.

3. Stabilized Backside via hole process
    Backside via hole process is one of the key processes. We succeed stabilization of this process.

4. Extended HBT life time
    Stable process and optimized epi-wafer conditions made the longer life time of our InGaP HBT
    possible.