Strained silicon on wafer level by wafer bonding: materials processing, strain measurements and strain relaxation

in ECS Transactions (2008), 16

Different methods to introduce strain in thin silicon device layers are presented. Uniaxial strain is introduced in CMOS devices by process-induced stressors allowing the local generation of tensile or ... [more ▼]

Different methods to introduce strain in thin silicon device layers are presented. Uniaxial strain is introduced in CMOS devices by process-induced stressors allowing the local generation of tensile or compressive strain in the channel region of MOSFETs. Biaxial strain is introduced by growing thin silicon layer on SiGe buffer and transferring it to an oxidized silicon substrates. The latter forms strained silicon on insulator (SSOI) wafer characterized by tensile strain only. Future CMOS device technologies require the combination of the global strain of SSOI substrates with local stressors to increase the device performance. [less ▲]

In-line characterization of hetero bipolar transistor base layers and pMOS devices with embedded SiGe by high-resolution x-ray diffraction

Poster (2008)

Fabrication, characterization, and modeling of strained SOI MOSFETs with very large effective mobility

in IEEE (Ed.) 37th European Solid State Device Research Conference (ESSDERC) (2007)

Strained silicon on insulators (sSOI) wafers with a supercritical thickness of 58 nm were produced using thin strain relaxed SiGe buffer layers, wafer bonding, selective etch back and epitaxial overgrowth ... [more ▼]

Strained silicon on insulators (sSOI) wafers with a supercritical thickness of 58 nm were produced using thin strain relaxed SiGe buffer layers, wafer bonding, selective etch back and epitaxial overgrowth. Raman spectroscopy revealed an homogeneous strain of 0.63 plusmn 0.03 % in the strained Si layer. Long channel n-type SOI-MOSFETs showed very large electron mobilities up to 1200 cm2/Vs in the strained Si devices. These values are more than two times larger than those of reference SOI n-MOSFETs. Mobility simulations with state of the art scattering models are then used to interpret the experiments. [less ▲]

In-line characterization of heterojunction bipolar transistor base layers by high-resolution x-ray diffraction

in ECS Transactions (2007), 10

The suitability of high-resolution X-ray diffraction (HRXRD) as an in-line measurement tool for the characterization of heterojunction bipolar transistor SiGe base layers and Si cap layers was ... [more ▼]

The suitability of high-resolution X-ray diffraction (HRXRD) as an in-line measurement tool for the characterization of heterojunction bipolar transistor SiGe base layers and Si cap layers was investigated. We showed that despite of polycrystalline Si on the mask material of patterned wafers, HRXRD measurements performed on an array of small windows yield results which are comparable to those that were obtained on a window which is larger than the size of the source beam, regarding the thickness and the Ge content of the SiGe layers. The possibility to extract layer parameters for active device windows of different sizes was therefore demonstrated. The suitability of HRXRD for in-line measurement of the Si cap thickness was also assessed and the sensitivity of this technique for determining the substitutional boron concentration in SiGe was studied. The detection limit in the monitoring of the active dopant concentration was about 2.7 × 1019 cm-3. [less ▲]

Large current enhancement in n-MOSFETs with strained Si on insulator

in International Semiconductor Device Research Symposium, 2007 (2007)

As scaling of the critical transistor dimensions below 65 nm has been slowed down, the implementation of novel materials, especially high mobility channel materials is most attractive to boost the ... [more ▼]

As scaling of the critical transistor dimensions below 65 nm has been slowed down, the implementation of novel materials, especially high mobility channel materials is most attractive to boost the transistor performance. Applying strain to silicon has become a successful route. The electron mobility can be enhanced by biaxial strain introduced into Si by epitaxial growth of Si on a strain relaxed SiGe layer or by so called process induced methods applied directly on transistor level. The combination of strained Si and SOI is particularly promising due to the combination of the enhanced mobilities and the inherent advantages of SOI. First long channel n-MOSFETs with gate lengths of 5 to 50 mum and a 6.6 nm thick SiO2 gate dielectric were fabricated. For comparison, devices on unstrained SOI were made. The transfer characteristics of a fully depleted sSOI-MOSFET with a gate length of 5 mum and a gate width of 20 mum indicating an inverse sub-threshold slope of 75mV/dec. [less ▲]

In-line characterization of heterojunction bipolar transistor base layers by high-resolution x-ray diffraction

Poster (2007)

In-line characterization of heterojunction bipolar transistor base layers by high-resolution x-ray diffraction

Conference (2007)