Properties of Schottky contact of Al on SiGe alloys

Abstract

Electrical properties of Schottky contacts of Al on p-Si1−xGex alloys were investigated. The Si1−xGex strained layers were grown on p-Si substrates by using rapid thermal process/very low pressure-chemical vapor deposition. Low reverse currents were obtained. It was found that the Schottky barrier height of Al/p-Si1−xGex contacts decreased with increasing Ge fraction. The decrement is in accordance with the decrement of the band gap of the strained Si1−xGex. The Fermi level at the interface is pinned at about 0.43 eV below the conduction band. The influence of strain relaxation for SiGe alloy layers and the Si sacrificial cap layers on the properties of Schottky contacts were also investigated.

Nonalloyed transparent ohmic contact of indium tin oxide to p-type Si0.8Ge0.2

“…This behavior may result from the fact that Ge atoms have enough energy to outdiffuse and segregate at the interface between the ITO and Si-capping layer since the Si-capping layer is very thin (30 nm). The Ge atom segregation would result in defects being generated and, hence, an ohmic contact is obtained [7,10]. The transmission line method (TLM) is used to Fig.…”

“…However, these ohmic contact electrodes were prepared indirectly onto SiGe layers through Si-capping layers to form refractory silicides in high-temperature alloying. It was reported [10,11] that the interfacial reaction of metal on an epitaxial Si 1Àx Ge x layer would involve a preferential reaction with Si, resulting in Ge segregation and Fermi level pinning. Thus, the Si-capping layer was used as a sacrificial layer to obtain a silicide contact to the Si 1Àx Ge x layer.…”

Schottky contact properties of Ni/n-poly-Si0.87Ge0.13/n-Si(100) heterostructure

“…Furthermore, formation and characterization of metal/ semiconductor interface have attracted considerable attention because of the scientific and technological significance [3]. In recent years, interfacial reaction and properties of Schottky contacts on Si 1 À x Ge x film for Pt, Pd, Ni, Ti, W, Al, Zr and Ir have been studied [4][5][6][7][8][9][10][11]. Most Si 1 À x Ge x films used in these research works are epitaxial and grown by molecular beam epitaxy (MBE) or chemical vapor deposition (CVD).…”

Rectifying characteristics of sputter-deposited SiGe diodes

“…For example, Schottky barrier height ͑SBH͒ of metal/poly-SiGe contact is not available though there are some reports on SBH of metal/epitaxial SiGe contact. [15][16][17][18][19][20][21][22][23] But the knowledge of SBH may be important for poly-SiGe's application in some cases, such as the elevated source/drain MOS device. This work presents the preparation of poly-SiGe Schottky barrier diode ͑SBD͒ and pn junction by IBS technique.…”