Particle formation during low-pressure chemical vapor deposition from silane and oxygen: Measurement, modeling, and film properties

Abstract

Particle generation in thermal chemical vapor deposition ͑CVD͒ processes can lead to the formation of contaminant particles that affect film properties and eventually device performance. This article reports on measurements of particle formation during low-pressure CVD of SiO 2 from silane and oxygen. Measurements of aerosol size distributions were made using a particle beam mass spectrometer ͑PBMS͒ and were carried out at pressures and temperatures ranging from 0.5 to 2.0 Torr ͑67-267 Pa͒ and 200-800°C, using an O 2 /SiH 4 ratio of 20. We found that within this parameter space, there are three different particle formation regions and a particle-free region. The particle formation regions include an explosion region ͓200-300°C, Pտ1.0 Torr ͑ϳ80 Pa͔͒, an unsteady region ͓400-600°C, Pտ0.8 Torr ͑ϳ107 Pa͔͒, and a steady region ͓700-800°C, P տ0.6 Torr ͑ϳ67 Pa͔͒. PBMS size analysis in the steady region shows that the size distributions are bimodal with one mode around 7 nm in diameter and the other around 20 nm, which is in reasonable agreement with transmission electron microscopy measurements. A numerical model was developed to simulate particle nucleation and growth in this system. The model predicts that for a given temperature, there exists a critical pressure above which abundant particle formation occurs and below which particle production is insignificant. The pressures for which particle formation was measured with the PBMS are in good agreement with model predictions, and measured and calculated particle sizes are in reasonable agreement. It is also found that there is a correlation between particle concentration and film surface morphology, dielectric constant, and currentvoltage characteristics of the film.

In-SituMeasurements of Charged Nanoparticles Generated During Hot Wire Chemical Vapor Deposition of Silicon Using Particle Beam Mass Spectrometer

“…The reliability of our assumption was examined in Figure S1 and PBMS DATA INVERSION section in the supporting information 3. The charged nanoparticles were classified by an electrostatic deflector which deflects charged nanoparticles in proportion to the ratio of the kinetic energy to charge by the induced critical deflection voltage (Kim et al 2002).…”

Real-Time Diagnosis of Nano-Sized Contaminant Particles Generated in TiN Metal Organic Chemical Vapor Deposition

“…Similarly, the influence of increasing pressure has been reported from the previous studies for particle formation during AlGaInN organometallic vapor phase epitaxy (OMVPE) 15) and SiO 2 low pressure CVD (LPCVD). 16) Figure 3(b) shows measurement results of particle distribution when using the TDMAT decomposed artificially by heating at 130 C for 36 h. In case of using decomposed TDMAT, The experiments reveal the distribution of the particle size to be trimodal with modes, $10, 35 -50, and 155 -180 nm, and new mode 35 -50 nm was generated. It is believed that the smaller particle generation is due to the reaction between decomposed chemical species.…”