Ultrathin Ge-on-Insulator Metal Source/Drain p-Channel Metal–Oxide–Semiconductor Field-Effect Transistors Fabricated By Low-Temperature Molecular-Beam Epitaxy

Abstract

We demonstrate the enhancement of hole mobility in an ultrathin Si/Ge/Si-on-insulator (SOI) channel metal-oxidesemiconductor field-effect transistor (MOSFET) with a metal source and drain (S/D). The ultrathin Si/Ge structure is fabricated on a SOI substrate by low-temperature molecular-beam epitaxy (LTMBE). We examined the impact of the Si/Ge/ Si structural parameters and the crystal quality on the electrical characteristics of MOSFETs, particularly from the viewpoints of the Ge thickness and the annealing temperature. As a result, the hole mobility of the fabricated Ge-on-insulator (GOI)-pMOSFETs after annealing at 600 C was found to be 1.2 times larger than the Si universal hole mobility. For the Ge thickness dependence of hole mobility, the MOSFETs with the Ge thicknesses of 8, 12, and 16 nm had almost the same mobility. On the other hand, the sample with 4 nm Ge thickness had lower mobility. For the annealing temperature dependence, the hole mobility had a maximum value at 600 C and decreased with increasing annealing temperature above 700 C.

The properties of the nanometer thick Si/Ge films‐on‐insulator produced by Ge+ ion implantation and subsequent hydrogen transfer

“…Although the carrier concentration decreased, the hole mobility rose from 115 cm 2 /Vs to 200 cm 2 /Vs as the MBE temperature was reduced from 800 to 700 o C. This means that the presence of Ge at the bonding interface of SOI structures results in an increase in the hole mobility by a factors of 3 and 5 for the MBE temperature of 800 and 700 o C, respectively. The obtained results are in good agreement with the data observed on the 20 nm thick SiGe-SOI heterostructures produced by MBE at the temperature of 600 o C [6]. An increase in the MBE processing temperature to 700 o C resulted in the drop of hole mobility from 200 to about 90 cm 2 /Vs [6].…”

“…The obtained results are in good agreement with the data observed on the 20 nm thick SiGe-SOI heterostructures produced by MBE at the temperature of 600 o C [6]. An increase in the MBE processing temperature to 700 o C resulted in the drop of hole mobility from 200 to about 90 cm 2 /Vs [6]. Analysis of these results evidences higher thermal stability of the structures formed by the Ge + ion implantation and subsequent hydrogen transfer.…”

Nanometer-thick SGOI structures produced by Ge+ ion implantation of SiO2 films and subsequent hydrogen transfer of Si layers

“…The obtained results show that the presence of Ge at the bonding interface of SOI structures results in an increase in the average hole mobility by a factors of 3 and 5 as compared with the respective Ge-free SOI structures prepared at MBE temperatures 800 and 700 o C. This is in good agreement with the data observed on 20 nm-thick SiGe-SOI heterostructures produced by MBE at the temperature of 600 o C [6]. An increase in the MBE processing temperature to 700 o C resulted in the drop of the hole mobility from 200 to about 90 cm 2 /Vs [6]. The analysis of these results evidences a higher thermal stability of structures formed by the Ge + ion implantation and subsequent hydrogen transfer.…”

“…The formation of heterostructures-on-insulator (HOI) is a way to increase the carrier mobility in the ultra-thin SOI transistors [4,5]. Recently, it was shown, that SGOI MOSFETs have the advantage of the enhanced drain-gate characteristics over the bulk silicon based devices [1,[4][5][6]. The reason of these advantages is the high hole mobility in the Ge matrix (about 1900 cm 2 /Vs).…”

Диффузия германия из захороненного слоя SiO-=SUB=-2-=/SUB=- и формирование фазы SiGe

“…Пленки Si 1−x Ge x обладают более высокими по сравнению с кремнием значениями подвижности носителей зарядов. Это обеспечивает большие крутизну и проводимость канала транзисторов, созданных на их основе [6][7][8][9]. Пленки Si 1−x Ge x нашли большое применение в так называемой БиКМОП технологии, объединяющей в одной интегральной схеме биполярные и КМОП транзисторы [10][11][12].…”