Interaction of Cu and Cu3Ge thin films with Si1−xGex alloys

Abstract

The interaction of Cu and Cu3Ge thin films with Si1−xGex (x=0.5) alloy layers epitaxially grown on Si(100) has been studied in the temperature range of 250–400 °C. In this temperature range, Cu reacts with the alloy to form a Cu3(Si1−xGex) ternary phase with an ordered body-centered-cubic crystal structure. The Cu3(Si1−xGex) phase exhibits high-room-temperature (∼150 μΩ cm) and nonmetallic resistivity. However, this ternary phase is not observed and the diffusion of Cu into the alloy is suppressed when Cu is replaced by low resistivity (typically less than 10 μΩ cm at room temperature) ε1-Cu3Ge phase. In contrast to the results reported for films of ε1-Cu3Ge formed on Si(100), the outdiffusion of Si into the ε1-Cu3Ge films is found to be suppressed when the films are formed on Si0.5Ge0.5 layers, indicating the increased stability of ε1-Cu3Ge on Si1−xGex alloys compared to pure silicon.

An Incommensurately Modulated Structure of η′-Phase of Cu3+xSi Determined by Quantitative Electron Diffraction Tomography

“…Cu 3 Si is used as a catalyst for the production of technologically highly important chlorosilanes, an intermediate compound in the production of ultrapure silicon for the semiconductor industry . Copper silicides and copper germanides have also been studied as materials for applications as contacts and interconnects in Si and Ge−Si electronic devices. , A large body of work has been published on the physical and chemical properties of Cu 3 Si; − on the growth mechanism and morphology of Cu 3 Si nanoparticles in silicon; − and on the formation of epitaxial layers of Cu 3 Si grown on oriented Si, Ge, or Si−Ge substrates. − …”

Epitaxial Cu3Ge Thin Film: Fabrication, Structure, and Property

“…Furthermore, the service life of Cu 3 Ge is considerably longer than Cu because the out-diffusion of Cu [4] is reduced. Not only different substrates have been used for growth of polycrystalline Cu 3 Ge films (including GaAs [5][6][7], Si [4,[8][9][10], Ge [10,11], YBa 2 Cu 3 O 7-x [12], Si x Ge 1-x [8,9,13], Ta/TaN [14] and GaN [15]), but also various deposition methods have been used for Cu 3 Ge thin film fabrication. For example, multiple physical vapor deposition methods, such as electron beam deposition, sputtering [1,2,4,11,12,16] and thermal evaporation [17], or chemical approaches such as vapor-solid reaction [14], have been exploited.…”

“…For example, multiple physical vapor deposition methods, such as electron beam deposition, sputtering [1,2,4,11,12,16] and thermal evaporation [17], or chemical approaches such as vapor-solid reaction [14], have been exploited. Despite the achievements in this field, the Cu 3 Ge films reported up to now were mostly polycrystalline with impurity phase [1,2,[4][5][6][7][8][9][10][11][12][13]. Consequently, Cu 3 Ge films with better crystallinity are highly desired, in order to minimize diffusion paths (grain boundaries) and lower electrical resistivity.…”

Effects of surface treatments on the electrical and the microstructural changes of Pd contact on p-type GaN

“…In GaN, Ga vacancies, V Ga , were known to be triply charged acceptors and N vacancies, V N , donors for electrons. 10,11 It was reported that WSi 0.79 layer on Te doped InP suppressed the outdiffusion of P, so the contact resistivity did not degrade up to 700°C. On the contrary, the production of V N in the subsurface region of p-type GaN results in an increase of contact resistivity.…”

“…On the contrary, the production of V N in the subsurface region of p-type GaN results in an increase of contact resistivity. 11 The role of S atoms at the metal/GaN interface, however, has not been studied yet. 9 A number of studies were conducted on the use of diffusion barriers to suppress the degradation of contact resistivity during annealing.…”