摘要:

The reactive ion etching of silicon(100) in Cl2/CCl4plasmas at 13.56 MHz is described.Insituellipsometry is used to determine the extent and nature of silicon surface roughening under a variety of plasma conditions. Quadrupole mass spectrometry yields complementary information regarding the composition of the plasma. In contrast to our previous experiments using pure Cl2, we find that no significant roughening of silicon occurs in Cl2/10%CCl4plasmas at 100 mTorr, irrespective of rf power in the range 50–300 W (0.3–1.8 W cm−2); indeed smoothing of previously roughened surfaces takes place at 100 mTorr and 100 W. When the plasma pressure is reduced to 50 mTorr, considerable roughening occurs at rf powers ≥100 W and a marked dependence on power is recorded. Water vapor has a far less dramatic effect on the etching and roughening of silicon(100) in Cl2/10%CCl4plasmas, compared to the effects observed in pure Cl2. This suggests that hydroxide micromasks are efficiently removed by reactive species that derive from CCl4. The mass spectrometric data support the hypothesis that it is CCl2and CCl3radicals that probably interact with>Si–OH to form COCl2and expose reactive silicon sites.

ISSN:0734-211X    

DOI:10.1116/1.585053

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

A two‐dimensional microtopography‐etch simulation using Monte Carlo methods presented earlier is used to simulate various reactive‐ion etch profiles. The simulation models the topography of an arbitrary, periodic semiconductor surface during plasma‐assisted or reactive‐ion etching. A plasma‐assisted etch process can be dominated by a physical (ion bombardment) mechanism, a chemical (free radical) mechanism or a physical/chemical interaction mechanism. Alternately recombinant surface chemistry can also determine the final etch profile. Examples of profiles generated under these three conditions are presented.

ISSN:0734-211X    

DOI:10.1116/1.585013

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

A new and practical via hole taper‐etching technology is proposed to obtain excellent step coverage of the upper metallization around the via holes in submicron multilevel interconnections. The technology uses incident‐angle dependency of sputter etching and etching selectivity of oxygen ions. A bias electron cyclotron resonance (ECR) plasma‐etching method is applied to realize a practical etching rate using oxygen ions. Scanning electron microscopy (SEM) inspection and contact string tests confirm that excellent results are obtained using the technology, including high yields and high reliability of submicron multilevel interconnections.

ISSN:0734-211X    

DOI:10.1116/1.585014

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

The deposition of thin silicon dioxide films using plasma enhanced and ozone assisted thermal chemical vapor deposition techniques and tetraethylorthosilicate (TEOS) as precursor in AME Precision 5000 reactor has been carried out. The properties of the oxide, such as etch rate, hydrogen concentration, dielectric constant, andC–Vbehavior, were investigated as a function of the deposition parameters, such as radio‐frequency (rf) power, gas composition, and temperature, and post rapid thermal annealing (RTA). The paper reports these results and discusses the findings. The electrical properties of these oxides, plasma, and ozone, were influenced primarily by water vapor that was absorbed and trapped into the bulk of the film either during or within a short time of deposition. The film quality can be considerably improved by RTA between 800 and 1000 °C.

ISSN:0734-211X    

DOI:10.1116/1.585015

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

Fluorinated silicon nitride films have been deposited by plasma‐enhanced chemical vapor deposition (PECVD) varying the relative [NF3]/([NH3]+[NF3]) flow ratio in the range 0–1. The as‐deposited films show an increase in the –NH radicals and a decrease in the –SiH radicals when the flow ratio increases above 0.5. In addition, these films are very unstable in hot water as well as in normal air atmospheres. The oxidation kinetics has been explained in terms of a direct oxidation reaction of the silicon nitride lattice accompanied by the formation of fluorinated complexes which also react with moisture to give finally SiO2.

ISSN:0734-211X    

DOI:10.1116/1.585016

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

The kinetics of the anodic oxidation of crystallinen‐type (100) silicon have been studied under room temperature conditions and in darkness. The initial stages of the oxidation process show an island‐type growth until the islands coalesce forming the oxide. The resulting films have been characterized by capacitance measurements, Rutherford backscattering spectrometry (RBS), nuclear reaction analysis (NRA), and infrared absorption spectroscopy (IR). Relevant parameters of the oxidation process such as the electric field of formation and the current efficiency were obtained. Combined NRA and IR analysis show a correlation between the Si–O bond absorption peak and the oxygen content of the SiO2films.

ISSN:0734-211X    

DOI:10.1116/1.585017

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

The N2–SiH4rf glow‐discharge plasma has been analyzed by line‐of‐sight mass spectrometry of species impinging on the deposition electrode (including N atoms), and properties of SiNxHyfilms deposited from this plasma have been examined. At high rf power and low SiH4/N2gas ratio, most of the SiH4is consumed by reaction of SiHmradicals with N atoms at the film surface and becomes incorporated into the film. No Si–N precursor species are seen in the plasma. This is in contrast to the NH3–SiH4plasma, where the Si(NH2)3radical is the key gas‐phase precursor. If power is insufficient or SiH4flow is excessive, disilane is formed in the plasma. Under disilane‐free plasma conditions, films slightly N rich with no Si–H bonding and only 11 at. % H (as N–H) can be deposited at high rate (21 nm/min). The film tensile stress characteristic of the NH3process is absent in the N2process due to the absence of precursor chemical condensation beneath the growing surface. However, step coverage is much worse in the N2process due to the much higher sticking coefficients of the reactant radicals. The N2plasma chemistry is the same using 400 kHz or 13 MHz rf power, but compressive stress and H content are both higher at the lower frequency due to H+implantation.

ISSN:0734-211X    

DOI:10.1116/1.585008

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

The purpose of this work is to measure the amount of H2O which is bound tightly in spin‐on‐glass (SOG) and the amount of reabsorption as a function of room air exposure time. Both results are needed in determining bake cycles and wait times prior to metal deposition when SOG is used in the dielectric stack of a multilevel metal system. About a tenth of the amount of gas which remains after a 2 h 150 °C bake is still present after a 2 h 350 °C bake. About half the amount of the tightly bound gas which is desorbed will be reabsorbed upon exposure to air in a period of 4 h or less. The time for half of the reabsorption to occur appears to be of the order of 20 to 60 min.

ISSN:0734-211X    

DOI:10.1116/1.585009

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

A relatively new method of removing hydrocarbon and silicone grease stains from silicon wafer surfaces is discussed. In this technique, high purity liquid or gaseous CO2is expanded in a special nozzle to form a high speed jet. The jet contains numerous small diameter particles of solid CO2. The CO2particles, referred to as snow, strike the surface and remove adherent particles (even submicron sizes), hydrocarbon stains such as fingerprints and noseprints, and silicone grease. Indeed, CO2snow cleaning of clean wafer surfaces has led to sizable reductions in the adventitious hydrocarbons; in one case, the reduction was about 60%. Surface analysis of clean and contaminated silicon wafers indicates that CO2snow cleaning causes no apparent chemical interactions and leaves no detectable residues.

ISSN:0734-211X    

DOI:10.1116/1.585010

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

Trenches in a layer of SiO2on Si, with feature sizes down to 0.125 μm have been filled with tungsten (W) using selective chemical vapor deposition (CVD). The trenches were formed in a fashion similar to contact vias by reactive ion etching the SiO2to the underlying silicon. The tungsten was then deposited in a cold wall CVD reactor, by silane reduction of WF6, to a thickness of 0.5 μm. The process results in good planarity and uniformity making it suitable for the fabrication of sub‐0.5 μm contacts and interconnects, and for the formation of high aspect ratio absorbers in x‐ray masks.

ISSN:0734-211X    

DOI:10.1116/1.585011

出版商:American Vacuum Society    

年代:1990

数据来源: AIP