Highly microcrystalline phosphorous‐doped Si:H very thin films deposited by RF‐PECVD

Alestair Wilson (1, 2) , Erwann Fourmond (2) , Bilel Saidi (1) , Benjamin Fornacciari (2, 3) , Solène Brottet (3) , Marc Juhel (1) , Mickael Gros-Jean (1)

1 ST-CROLLES - STMicroelectronics [Crolles]
2 INL - I-Lum - INL - Ingénierie et conversion de lumière (i-Lum)
3 INL - Nanolyon - INL - Plateforme Technologique Nanolyon

Finely tuning crystallinity and doping of hydrogenated microcristalline silicon thin films is a keypoint into obtaining high quality devices for above integrated circuit (above-IC) image sensors. This study focuses on the structural and electrical properties of RF-PECVD deposited microcrystalline silicon (µc-Si:H) contact layers. In this work, phosphorus doped µc-Si:H is deposited by capacitive coupled plasma RF-PECVD (13,56 MHz) from a SiH4 + H2 + PH3 gas mixture with varying phosphine concentration. The influence of phosphine concentration on dopant concentration, active dopant concentration and crystallinity is studied by SIMS, Hall effect measurement and Raman spectroscopy respectively. High doping level is attained, reaching up to 1.7×10 20 cm-3. Furthermore, "low power" and "high power" deposition conditions are studied which lead to incubation layers of different nature.

Mots clés: PECVD; Microcrystalline Silicon; PH3

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Micro et nanotechnologies/Microélectronique

Alestair Wilson, Erwann Fourmond, Bilel Saidi, Benjamin Fornacciari, Solène Brottet, et al.. Highly microcrystalline phosphorous‐doped Si:H very thin films deposited by RF‐PECVD. physica status solidi (a), 2022, ⟨10.1002/pssa.202100876⟩. ⟨hal-03657259⟩