Details

Autor(en) / Beteiligte

• Resnik, D.
• Kovač, J.
• Vrtačnik, D.
• Godec, M.
• Pečar, B.
• Možek, M.

Titel

Microstructural and electrical properties of heat treated resistive Ti/Pt thin layers

Ist Teil von

• Thin solid films, 2017-10, Vol.639, p.64-72

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• Study of DC sputtered Ti/Pt thin film layers on SiO2/n-Si substrate with the emphasis on post deposition heat treatment is presented. Microstructural and morphological properties of Ti/Pt thin films annealed in the range 300–700°C in air are investigated and correlated with measured electrical properties. AES depth profile and composition of the sample annealed at 400°C and 700°C showed significant diffusion of Ti throughout the Pt layer toward surface, accompanied with enhanced oxygen incorporation, while keeping rather constant TiOx composition throughout the structure. AFM and SEM analyses of Ti/Pt film morphology showed that Pt grain size was almost temperature independent up to 400°C, while above 500°C, grain growth was enhanced. XPS analyses confirmed that most of Ti incorporated in the film was in oxide state (Ti4+) after annealing at 700°C. EBSD analyses confirmed strong (111) texture of Pt polycrystalline grains annealed above 500°C. Resistance of meandered Ti/Pt resistors was found to decrease significantly above 500°C and complies well with the microstructural rearrangements determined by AFM and AES analyses. It was further determined that by increasing the annealing temperature from 300°C to 700°C, a monotonic increase of temperature coefficient of resistance from 1400ppm/°C to 2400ppm/°C, respectively, was obtained. This represents a considerable improvement in sensitivity of Ti/Pt layers used as a temperature sensing devices. Resistance exhibited linear temperature dependency with nonlinearity better than 0.84%. •Increase of Ta enhanced Ti and O incorporation in Pt layer, approaching Ti4+ state.•Noteworthy Pt grain growth and strong (111) texture determined for Ta>500°C.•Decrease of Ti/Pt resistivity for Ta>500°C due to grain growth and GB reduction•TCR monotonically increased with Ta (50% at Ta=700°C vs. as deposited Ti/Pt).•Annealing at Ta≥700°C revealed reduced adhesion at (Ti/Pt)/SiO2 interface.