摘要:

Process characterization details are reported for the first time, to the best of our knowledge, for plasma enhanced chemical vapor deposition of silicon nitride films using disilane as silicon source. Respectable deposition rates have been realized even under the conditions of low mass flow rates of disilane(<1 sccm)and large dilution of process gases with helium. The film uniformity (<±3%thickness variation across 4 in. diameter wafers) and process repeatability in this gas system were found to be excellent. The deposition rates were examined as a function of gas flow ratio, rf power, process pressure, and deposition temperature. Similar to a silane based process, two regimes of operation, namely ammonia-rich and disilane-rich, were identified. Films deposited at the boundary of these two regimes were nitrogen rich and had deposition rates that were dependent only on disilane to ammonia flow ratio and rf power and nearly independent of process pressure and deposition temperature. The hydrogen concentration of these films was found to be nearly constant over the investigated range of ammonia to disilane flow ratio values varying from 4 to 20. Also, the variation in H concentration in these films with deposition temperature was smaller than what is reported for silane based films. The choice for process parameters based on rf power, utilization of disilane, deposition rate, and film stoichiometry is given.

ISSN:1071-1023    

DOI:10.1116/1.590011

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

A study of moderatelyin situdoped polycrystalline silicon deposition fromSiH4, PH3,andH2by single-wafer reduced pressure chemical vapor deposition has been carried out. The process window which yielded P concentrations on the order of1019 cm−3was a pressure of 80 Torr in a hydrogen carrier with aPH3/SiH4mole fraction range of0.1×10−4–1×10−4,and temperatures of 600–700 °C. It was found that thePH3/SiH4mole fraction in this process window has little effect on the deposition rate unlike the rate reduction caused byPH3in a saturation-doped polysilicon process with doping levels in excess of1020 cm−3.The activation energy of the process, 48kCal mol−1,over this temperature range approaches one of a hydrogen desorption limited process, 49kCal mol−1,suggesting that the deposition rate is dominated by the highH2pressure. The transition of the as-deposited film structure from predominately amorphous to completely polycrystalline occurs at about 675 °C, about 100 °C higher than in typical low-pressure chemical vapor deposition and is likely due to a combination of highH2pressure and high deposition rates. To a first order, the post-anneal film resistivity appears to be dominated by the grain structure and not by the P incorporation rate in the moderately doped concentration regime.

ISSN:1071-1023    

DOI:10.1116/1.590012

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

Silicon oxynitride thin films have been deposited using remote plasma chemical vapor deposition fromSiCl4+NH3+O2gas mixtures. The stoichiometry of the deposited films varies from that corresponding to the silicon oxide to a stoichiometry very close to silicon nitride when theNH3/O2gas ratio is changed in the plasma. The approximate compositions of the films were determined by Rutherford backscattering spectroscopy and nuclear reaction analysis, and the local bonding arrangements were determined by infrared spectroscopy. Analysis of metal–insulator–semiconductor devices under the effect of and external sinusoidal electric field (dielectric spectrometry) indicates the presence of traps centers in theSi–SiO2interface. Correlations between the local bonded structures in the oxynitride and the conduction and polarization processes detected in the films are also discussed.

ISSN:1071-1023    

DOI:10.1116/1.590013

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

Global planarization technology based on a new concept comprised of spin on glass (SOG) film transfer and hot pressing is proposed for interlayer dielectrics. The technology basically involves coating a SOG film onto a sheet film in advance and then transferring it from the sheet film to a Si substrate by pressing and heating it in a vacuum. Planarization and filling of the interlayer dielectrics can be carried out by this process. For this technology, perhydrosilazane, which has a high viscosity for a thick formation during coating and a low viscosity for the flow during heating, is used as the SOG material. Experimental results show that the SOG thickness is reduced by the pressing and heating process and that its uniformity can be improved by the press force. By applying this technology to Al interconnection, it is found that planarization and filling can be completely realized. Therefore, this technology is very promising for simple and inexpensive global planarization.

ISSN:1071-1023    

DOI:10.1116/1.590014

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

CeO2thin films were grown on Si(100) and Si(111) substrates by radio frequency-magnetron sputtering. The growth temperature and the substrate orientation have significant influences on the preferred orientations of depositedCeO2films. X-ray diffractometry and transmission electron microscopy analyses showed thatCeO2on Si(111) has a better preferred orientation in the direction of the substrate orientation thanCeO2on Si(100).CeO2films deposited on Si(111) substrates maintain a preferred orientation better thanCeO2films on Si(100), when they are subjected to annealing at 900 °C inO2atmosphere for 30 min. Rutherford backscattering spectra taken ofCeO2/Sibefore and after annealing showed thatCeO2has strong thermal stability.

ISSN:1071-1023    

DOI:10.1116/1.590015

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

A directional copper deposition process has been developed that uses a dc magnetron source operating in self-sputtering mode. The process is performed at10−5 Torrrange pressure where a “long throw” approach can be utilized without discharge enhancement or mechanical collimation due to a very long mean free path of sputtered species. Magnetron sputtering conditions at which the contact hole filling is promoted and substantially enhanced by the self-sputtering process are illustrated and compared to standard sputtering (i.e., short throw, mTorr pressure) in the presence of argon. The experimental parameters of the new process have been explored by depositing Cu on patterned Si wafers with trenches and contact holes of various aspect ratios.

ISSN:1071-1023    

DOI:10.1116/1.590016

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

The effects of surface cleaning procedures on the subsequent reactivity of a pure copper thin film to silane was investigated.Ex situ, wet etching andin situdry, plasma etching using inert and reducing chemistries were employed. A few seconds low power (50 W) plasma exposure using a 3 vol% hydrogen in argon gas mixture was found to be the most beneficial technique for subsequent silicide formation by the silane exposure technique.

ISSN:1071-1023    

DOI:10.1116/1.590017

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

A surface of polytetrafluoroethylene (PTFE) was modified with changing ion doses by 1 keVAr+ion irradiation and Cu films with a 5000 Å were deposited on the modified PTFE. The scanning electron microscopy study showed that the surface texture of modified PTFE was in the form of filaments whose height increased depending on ion doses. Through x-ray photoelectron spectroscopy spectra, it was found that the intensity ofF 1speaks decreased with ion doses by preferential sputtering of F atoms and the C–C and/or C–F chains were formed by the crosslinking in the newly unstable chains. Cu films were deposited uniformly along the filaments formed on the modified PTFE. In x-ray diffraction spectra of deposited Cu films on modified PTFE, a preferred orientation along (111) and (200) planes was found and a relative intensity of(111)/(200)orientation increased as surface roughness of modified PTFE increased. The resistivity of Cu films was changed from 2.7 μΩ cm of unmodified PTFE to 4.3 μΩ cm of modified PTFE at an ion dose of1×1016/cm2and the abrupt increase of resistivity in the modified PTFE at an ion dose of1×1017/cm2was due to being cut off the film which resulted from the increased surface roughness.

ISSN:1071-1023    

DOI:10.1116/1.590018

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

When a thin film is deposited by physical vapor deposition, with the vapor flux arriving at an oblique angle from the substrate normal, and under conditions of sufficiently limited adatom mobility to create a columnar microstructure, the resulting structure is somewhat porous and grows at an angle inclined toward the vapor source. For a given material and set of deposition conditions, there is a fixed relationship between the angle of vapor flux incident on the substrate and the inclination angle at which the columnar thin film grows. As the porosity of the film is also dependent on the incident flux angle, column growth angle and porosity cannot be chosen independently. If a large columnar angle (more parallel to the substrate) is desired, the flux must be deposited at a large oblique angle resulting in a very porous film. Conversely, if a near vertical columnar film is desired, the flux must arrive more perpendicular to the substrate and the resulting film has a tightly packed, dense microstructure. We present a technique, based on glancing angle deposition, employing substrate motion during deposition, which allows the columnar growth inclination angle and film density to be controlled independently. With this method, microstructurally controlled materials can be fabricated with three dimensional control on a 10 nm scale for use in optical, chemical, biological, mechanical, magnetic, and electrical applications.

ISSN:1071-1023    

DOI:10.1116/1.590019

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

High-density plasma chemical vapor deposition (HDP CVD) is a deposition method of current interest for gap fill of intermetal and interlevel dielectrics in semiconductor circuits. In HDP CVD processes the silicon dioxide film is often sputter etched as it is being deposited. The resputtering of the deposited film is a crucial process component in determining the final surface topography. Hence, it is imperative that the process simulators take this effect into consideration. In this work, we propose a method to extract the angle-dependent sputter yield for the HDP CVD process. This method constitutes the usage of our test structure. The extracted angular yield distribution is, then, used to simulate the final silicon dioxide profile. The distribution validity is determined by comparison of the simulated profile against the experimental profile.SPEEDIE(Stanford profile emulator for etching and deposition in integrated circuit engineering), a deposition and etching simulation program, was used as the simulator while experiments were performed on a HDP CVD system. A reasonably, good agreement was obtained between simulated and experimental profiles, indicating an accurate angular yield extraction. The extracted angular yield curve was compared with other such curves from literature for different ion energies. This comparison showed a trend of increase in the angle at which maximum yield occurs as the ion energy increased.

ISSN:1071-1023    

DOI:10.1116/1.590020

出版商:American Vacuum Society    

年代:1998

数据来源: AIP