Modeling and optimization of the step coverage of tungsten LPCVD in trenches and contact holes
- Faculty of Electrical Engineering, Univ. of Twente, 7500 AE Enschede (NL)
- Faculty of Applied Physics, Delft Univ. of Technology, 2600 GA Delft (NL)
In this paper a model is presented to calculate the step coverage of blanket tungsten low pressure chemical vapor deposition (W-LPCVD) from tungsten hexafluoride (WF{sub 6}). The model can calculate tungsten growth in trenches and circular contact holes, in the case of the WF{sub 6} reduction by H{sub 2}, SiH{sub 4}, or both. The step coverage model predictions have been verified experimentally by scanning electron microscopy (SEM). The authors found that the predictions of the step coverage model for the H{sub 2} reduction of WF{sub 6} are very accurate, if the partial pressures of the reactants at the inlet of the trench or contact hole are known. To get these reactant inlet partial pressures, the authors used a reactor model which calculates the surface partial pressures of all the reactants. These calculated surface partial pressures are used as input for the authors' step coverage model. In this study the authors showed that thermodiffusion plays a very important role in the actual surface partial pressure. In the case where SiH{sub 4} was present in the gas mixture trends are predicted very well but the absolute values predicted by the step coverage model are too high. The partial pressure of HF, which is a by-product of the H{sub 2} reduction reaction, may be very high inside trenches or contact holes, especially just before closing of the trench or contact hole. The authors found no influence of the calculated HF partial pressure on the step coverage.
- OSTI ID:
- 5339417
- Journal Information:
- Journal of the Electrochemical Society; (United States), Journal Name: Journal of the Electrochemical Society; (United States) Vol. 138:6; ISSN 0013-4651; ISSN JESOA
- Country of Publication:
- United States
- Language:
- English
Similar Records
In situ monitoring of the products from the SiH[sub 4] + WF[sub 6] tungsten chemical vapor deposition process by micro-volume mass spectrometry
A microstructural study of LPCVD tungsten thin films for use as contact material to silicon
Related Subjects
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400400 -- Electrochemistry
CALCULATION METHODS
CHEMICAL COATING
CHEMICAL REACTIONS
CHEMICAL VAPOR DEPOSITION
DATA
DEPOSITION
DIFFUSION
ELECTRIC CONTACTS
ELECTRICAL EQUIPMENT
ELECTRON MICROSCOPY
ELEMENTS
EQUIPMENT
EXPERIMENTAL DATA
FILMS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN
INFORMATION
LOW PRESSURE
METALS
MICROSCOPY
NONMETALS
NUMERICAL DATA
OPTIMIZATION
REDOX REACTIONS
REFRACTORY METAL COMPOUNDS
SCANNING ELECTRON MICROSCOPY
SURFACE COATING
THERMAL DIFFUSION
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TUNGSTEN
TUNGSTEN COMPOUNDS
TUNGSTEN FLUORIDES