Impact of PECVD-prepared interfacial Si and SiGe layers on epitaxial Si films grown by PECVD (200 °C) and APCVD (1130 °C)

Abstract

The homoepitaxy of Si is particularly interesting for the purpose of kerfless wafer production, for example in the photovoltaic domain. Substrate surface engineering is a key step prior to epitaxial growth, which will affect the quality of the epitaxial layer and its detachment for layer transfer. In this work, we propose two plasma-based surface engineering methods including the deposition of a bilayer homoepitaxial interface and a SiGe heteroepitaxial interface. Their impact on the crystalline quality of epitaxial Si layers grown both by plasma enhanced chemical vapor deposition (PECVD) at 200 °C and by atmospheric pressure chemical vapor deposition (APCVD) at 1130 °C are explored. Stacking faults are observed in epitaxial Si layers with an ultra-thin epitaxial Si interface layer. For surface engineering method based on the 2 addition of an interfacial heteroepitaxial SiGe layer, higher interfacial hydrogen content and better bulk epitaxial Si quality are observed in comparison with interfacial homoepitaxial Si layer.

Fabrication of Crystalline Si Thin Films for Photovoltaics

“…Moreover, changes in doping levels during growth may also be caused by the cooling process. [106] When considering the epitaxy from a gas precursor, hightemperature approaches (between 800 and 1200 °C), such as chemical vapor deposition (CVD) [108,109] (see Figure 12a), are commonly used because thermal activation helps incoming Si atoms to settle in crystalline sites. However, high-temperature methods face a number of challenges, including high thermal budget, dopant diffusion, thermal mismatch, and incompatibility with lowcost substrates.…”

“…below 500 °C [122] (see Figure 12f,g), high-vacuum electron cyclotron resonance plasma deposition epitaxy with temperatures in the range of 450-525 °C, [123] ion beam epitaxy using temperatures of above 300 °C, [124][125][126][127] electron cyclotron resonance plasma CVD (ECR-CVD) using temperatures as low as 285 °C, [128] laser-enhanced chemical vapor deposition at temperatures as low as 250 °C [129] and plasma-enhanced chemical vapor deposition (PECVD) (see Figure 12b,c) using temperatures in the range of 700 °C and down to 150 °C. [44,79,95,109,[130][131][132] It should be emphasized that PECVD is the only technique that has allowed to produce thick c-Si films at low temperatures. Regardless of the application and manufacturing technology, in order to process the thin and fragile epitaxial c-Si films, they must be transferred to foreign carriers such as glass [79] or to flexible substrates such as metal foil, [133] plastic [134] and polyimide.…”

“…[95,132] This technology has been shown to be able to produce a hydrogen-rich Si interface layer [44,79] and Si-germanium alloy interface layer. [109] As a result, a brittle epi-PECVD/wafer interface is created, allowing for facile layer detachment. The quantity of hydrogen incorporated, which can be controlled via the PECVD process parameters, determines the degree of interface weakening.…”

Palladium-Alloy Membrane Reactors for Fuel Reforming and Hydrogen Production: A Review

“…MOCVD deals with metal/organic deposition under a vacuum. Lastly, in the AACVD and ALCVD deal with the substrate deposition in altering layers. , …”

“…Lastly, in the AACVD and ALCVD deal with the substrate deposition in altering layers. 119,120 4.3. Physical-Vapor Deposition (PVD).…”