InGaAs MOSFET Epi Structure *S

III-V compound semiconductor materials are expected to have significant improvements over Si, germanium, and other elemental semiconductors due to their electronic band structure and material properties, such as higher electron mobility. The InGaAs material properties are between GaAs and InAs, depending on the ratio of Ga to In. Researchers have found that III-V heterostructures have become the most important material for N-channel FETs due to their higher mobility. Many researchers are working on using InGaAs and other III-V compound semiconductors as high mobility channel materials in silicon-based FETs for mainstream complementary MOS technologies. PAM-XIAMEN can epitaxially grow quantum-well (QW) InGaAs MOSFET (metal oxide semiconductor field-effect transistor) wafers, and the specific structure is as follows for reference only：

1. InGaAs MOSFET Epi-Structure

2. Role of InP Etching Stop Layer in InGaAs Quantum-Well MOSFETs

Due to its good conduction band offset, InP is an excellent barrier and passivation layer that enhances the current driving capability of these devices, especially for In0.7Ga0.3As QW MOSFETs.

In addition, the InP barrier layer separates the medium from the InGaAs channel. Due to the higher potential barrier of InP compared to InGaAs, a large number of electrons can accumulate on the surfaces of InP and InGaAs. Compared with surface channels, it can reduce the influence of scattering mechanisms such as surface roughness scattering and phonon scattering of channel carriers on channel mobility.

3. Why Select InGaAs as Channel Material for MOSFET?

Firstly, due to its higher mobility, good oxide interface, and low energy bandgap, InGaAs is an emerging semiconductor material. By using InGaAs and high-K dielectric in the band, larger band orders can be achieved, making it easier to achieve low gate leakage and low static power consumption. At present, the effective channel mobility of InGaAs as a channel MOSHEMT device can exceed 5000 cm2/(V · s), which is 8 times that of silicon MOSFET devices, and the intrinsic delay time of InGaAs channel MOSFET devices is shorter than that of silicon devices.

Secondly, the strong inversion surface potential change of InGaAs channel is much smaller than that of GaAs channel. More importantly, the charge neutral energy level of In0.65Ga0.35As is typically 0.15 eV lower than the minimum value of the conduction band. This can prevent the accumulation of a large amount of negative capture charges at the interface, which can suppress the introduction of additional counter current carriers due to field effects.

In addition, studies have shown that the higher the In composition, the lower the threshold voltage of MOSFET devices. This is because the dielectric constant of high In component InGaAs materials themselves is higher than that of low indium(In) content InGaAs materials, resulting in a lower threshold voltage for high In content InGaAs channel MOSFETs than for low In content InGaAs channel MOSFETs. That is to say, low In content InGaAs MOSFETs are more suitable for making enhanced devices.

N-channel small bandgap InGaAs MOSFETs have become very popular due to their abundant availability and high performance in small signal RF and digital logic circuits. With the advantages of high electron mobility, low bandgap, and superior injection speed of InGaAs MOSFETs, these transistors have become suitable candidates for VLSI, digital circuits, and high-speed applications.

Whether you need InGaAs epi wafers for research or for industrial applications, please contact us email at [email protected] and [email protected].