Intel to use Ge & InGaAs to Speed Up Transistors
Ge P-channel transistors could potentially be combined with complementary III-V N-channel transistors to form a suitable CMOS architecture. This would provide higher mobility and could potentially lead to processors with higher performance and better energy efficiency.
Intel continues to push the forefront of transistor research to ensure the continuation of Moore’s Law. The company is trying to shrink transistors and pack more functionality into each processor, whilst also making them faster and more energy efficient.
One very active area of research is in the use of compound semiconductors to form the transistor channel, replacing silicon which is in use for the channel today.
In a paper highlighted by the IEDM, Intel researchers describe compound semiconductor transistors with high-K gate dielectrics that are non-planar and hence more amenable to continued shrinking. These devices are multi-gate Quantum Well Field Effect Transistors (QW-FET) with undoped III-V (InGaAs) channels in the shape of a vertical fin to permit simultaneously higher performance and lower power consumption. They also exhibit high-k gate dielectric and a greater enhancement-mode threshold voltage and have significantly improved electrostatics.
The development of future processes requires a large tool box of transistors with a broad choice of materials and structures to choose from for deciding which will scale best for manufacturing faster, denser and more energy-efficient processors.
Intel researchers developed P-channel transistors using germanium (Ge) that show the highest hole mobility reported for any Ge device to date. While Ge is not a III-V material, Ge P-channel transistors could potentially be combined with complementary III-V N-channel transistors to form a suitable CMOS architecture. Higher mobility can potentially lead to processors with higher performance and better energy efficiency.
The Germanium P-channel Quantum Well Field Effect Transistor (QW-FET) has an architecture that incorporates biaxial strain and minimizes dopant impurity scattering. Parallel conduction in the SiGe buffer was suppressed using a phosphorus junction layer.
The Ge QWFET achieves an intrinsic transconductance that is two times higher than the InSb p-channel QWFET.
Intel claims the drive current at fixed Ioff is two times better than the best III-V and Ge devices reported to date.