Excimer laser-assisted etching of polysilicon at 193 nm

1987 ◽  
Vol 2 (6) ◽  
pp. 895-901 ◽  
Author(s):  
M. D. Armacost ◽  
S. V. Babu ◽  
S. V. Nguyen ◽  
J. F. Rembetski
Keyword(s):  
Gas Phase ◽  
Excimer Laser ◽  
Cross Section ◽  
Thermal Effects ◽  
Etch Rate ◽  
Sem Analysis ◽  
Surface Roughening ◽  
193 Nm ◽  
Limiting Value ◽  
Scanning Electron

Excimer laser-assisted etching of polysilicon at 193 nm was studied in the presence of CF3Br, CF2Cl2, and NF3. In the presence of 193 nm radiation, CF3Br showed some propensity to etch polysilicon, while CF2Cl2 did not show any appreciable etching. In the presence of NF3, maximum etch rates of 0.6 Å/pulse were obtained for pressures greater than 500 Torr and fluences exceeding 200 mJ/(cm2 pulse). The etch rate increased with both fluences and pressure to a limiting value of 0.6 Å/pulse. An adsorptive etch mechanism was proposed, where NF3 molecules diffuse to the surface, adsorb, and then react after absorbing laser radiation. Thermal effects enhance this process and appear to dominate at lower pressures (<400 Torr) and higher fluences. Etching caused by the gas phase formation of F atoms is minimal due to the low absorption cross section of NF3 at 193 nm. Etching of submicron profiles in polysilicon was also examined. Polysilicon samples masked by patterned SiO2 were exposed to NF3 and 193 nm ArF radiation. Subsequent scanning electron microscopy (SEM) analysis demonstrated directional etching with some surface roughening.

193-Nm Excimer Laser-Assisted Etching of Polysilicon Films Using Cl2

1987 ◽  
Vol 101 ◽  
Author(s):  
Son Van Nguyen ◽  
S. Fridmann ◽  
J. Rembetski
Keyword(s):  
Gas Phase ◽  
Excimer Laser ◽  
Cross Section ◽  
Thermal Effects ◽  
Etch Rate ◽  
Absorption Cross ◽  
Molecular Flux ◽  
Polysilicon Films ◽  
193 Nm ◽  
Cl Atoms

ABSTRACT193-nm excimer laser-assisted etching of polysilicon was studied in the presence of CI2. Maximum etch rates of 1.25 Å/pulse were obtained for pressures of about 400 torr and fluences exceeding 400 mJ/(cm2-pulse). The etch rate increased with both fluence (100-550 mJ/(cm2-pulse)) and pressure (50-800 torr). An adsorptive etch mechanism similar to NF3 etching has been proposed, where Cl2 molecules diffuse to the surface, adsorb, and then react after absorbing laser radiation. This is consistent with photon and molecular flux considerations and the availability of reaction sites. Thermal effects where Cl2 molecules decompose to Cl atoms on “hot” polysilicon surfaces may assist this process, and appear to dominate under conditions of lower pressure (<400 torr) and higher fluence. Etching caused by the gas phase formation of Cl atoms is minimal due to the low Cl2 absorption cross section at 193 nm.Simple projection etching results showed that micron lines can be etched in polysilicon by use of this chemistry.

Two-Photon Absorption Cross Section for Silane Under Pulsed Arf (193 nm) Excimer Laser Irradiation

1987 ◽  
Vol 101 ◽  
Author(s):  
C. Fuchs ◽  
E. Boch ◽  
E. Fogarassy ◽  
B. Aka ◽  
P. Siffert
Keyword(s):  
Excimer Laser ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Incident Light ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Excimer Laser Irradiation ◽  
193 Nm

ABSTRACTWe have determined for the first time, the two-photon absorption cross-section of silane at 193 nm, by measuring directly the fraction of incident light absorbed in the gas phase during the irradiation with a pulsed ArF excimer laser.

Single-Crystal Silicon Etching Characteristics Using Excimer Laser Cℓ2 GAS

1983 ◽  
Vol 29 ◽  
Author(s):  
T. Arikado ◽  
M. Sekine ◽  
H. Okano ◽  
Y. Horiike
Keyword(s):  
Single Crystal ◽  
Gas Phase ◽  
Excimer Laser ◽  
Plasma Etching ◽  
Etch Rate ◽  
Single Crystal Silicon ◽  
Silicon Etching ◽  
Crystal Silicon ◽  
Direct Irradiation ◽  
P Type

ABSTRACTSingle-crystal Si etching characteristics using an excimer laser (308 nm, XeCℓ) in the Cℓ2 gas have been studied. In lightly doped n-type and p-type Si, the etch rate of (100) is higher than that of (111), thus the (111) sidewall appears clearly for the irradiation to (100), while both orientations show almost the same etch rates in n+-doped Si. The n-type Si is etched spontaneously even by photo-dissociated Cℓ radicals generated in the gas phase, but no p-type Si etching occurs without direct irradiation. In addition, both types of etch rate-dependence on sheet resistance demonstrate that the number of electrons in the conduction band plays an essential role in the Si etching. This fact supports the field-assisted mechanism in the plasma etching proposed by Winters.

A Comparison of the Gas Phase Processes Resulting from SiH4 and Si2H6 Photodissociation with a Pulsed ArF Excimer Laser

1988 ◽  
Vol 129 ◽  
Author(s):  
E. Boch ◽  
C. Fuchs ◽  
E. Fogarassy ◽  
P. Siffert
Keyword(s):  
Gas Phase ◽  
Excimer Laser ◽  
Laser Energy ◽  
Initial Pressure ◽  
Laser Pulses ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Deposition Yield ◽  
193 Nm

ABSTRACTWe present in this paper a comparison of the photodissociation processes of SiH4 and Si2H6 under pulsed excimer laser at 193 nm. The experimental curves of the gas composition as a function of laser energy density show that the dissociation of Si2H6 results from both one and two-photon absorption whereas SiH4 only absorbs two photons. The deposition yield of Si2H6 has also been determined as a function of the number of laser pulses or initial pressure. These experimental results show the establishment of a stationary state in the gas phase and prove the existence of reverse reactions in the disilane kinetic model. The photodissociation of Si2H6 under UV laser excitation (193 nm) presents, therefore, similar properties to those of SiH4.

Modeling of Silicon Deposition Yield at Low Temperature by ArF Excimer Laser Photolysis of Disilane

1992 ◽  
Vol 263 ◽  
Author(s):  
B. Fowler ◽  
S. Lian ◽  
S. Krishnan ◽  
C. Li ◽  
L. Jung ◽  
...  
Keyword(s):  
Gas Phase ◽  
Excimer Laser ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Film Deposition ◽  
Growth Surface ◽  
Phase Reaction ◽  
Gas Phase Reactions ◽  
Arf Excimer Laser ◽  
193 Nm

ABSTRACTNon-thermal Chemical Vapor Deposition (CVD) such as laser-enhanced photo-CVD of Si at low temperatures is important for Si-based heterostructures and doping superlattices. Growth kinetic models must be developed to allow these processes to be fully exploited. Intrinsic Si epitaxial layers were deposited at low substrate temperatures of 250-350ºC using the 193 nm output of an ArF excimer laser to directly dissociate Si2H6. The intrinsic film deposition rate can be described by a kinetic model that considers the gas phase reactions of the primary photolysis products and diffusion ofsilicon-bearing molecules to the growth surface. With the laser beam tangential to the substrate surface, growth rates as a function of beam-to-substrate distance have been characterized and indicate that very little gas phase reaction occurs for the dominant Si growth precursor. In order for intrinsic film deposition to result solely from Si2H6 photolysis products, a sticking coefficient ≥ 0.6 must be assigned to the dominant growth precursor in order to fit the observed yield of Si deposited in the films, indicating that the dominant growth precursor in 193 nm Si2H6 photolysis is perhaps H2SiSiH2.

X-Ray Photoemission Investigation of Excimer Laser Induced Etching of InP

1989 ◽  
Vol 158 ◽  
Author(s):  
R. Matz ◽  
J. Meiler ◽  
D. Haarer
Keyword(s):  
Gas Phase ◽  
Excimer Laser ◽  
Spatial Resolution ◽  
Etch Rate ◽  
Large Area ◽  
X Ray ◽  
Resolution Capability ◽  
Fundamental Understanding ◽  
Arf Excimer Laser ◽  
Laser Induced Etching

ABSTRACTArF excimer laser induced etching of InP in various etch gases (HBr, HCI, CI2) is discussed with regard to its spatial resolution capability. X-ray photoemission spectra and large-area etch rate measurements published before lead to fundamental understanding and interpretation of the characteristics of etched test structures. HBr and HCI require gas phase photodissociation. CI2' in contrast, has the advantage to react spontaneously.

Excimer Laser Induced Photolytic Deposition of Aluminum Nitride: Ftlm Growth and Properties

1995 ◽  
Vol 397 ◽  
Author(s):  
G. Radhakrishnan ◽  
P.M. Adams ◽  
N. Marquez
Keyword(s):  
Electron Microscopy ◽  
Aluminum Nitride ◽  
Substrate Temperature ◽  
Gas Phase ◽  
Excimer Laser ◽  
Film Growth ◽  
Aln Film ◽  
Fused Quartz ◽  
Photolysis Laser ◽  
193 Nm

ABSTRACTExcimer laser photolysis has been used for the growth of smooth and well-adhering thin films of aluminum nitride (AlN) on Si, fused quartz, and KBr substrates at temperatures as low as 350 K. The photolysis was carried out at 193 nm, with the laser beam propagating parallel to the substrate. Trimethylamine alane and ammonia were used as gas-phase precursors. The growth rate of these films was investigated as a function of laser fluence. These measurements, as well as other investigations of film growth with and without the photolysis laser, reveal that no AlN film is produced in the absence of laser-induced photolysis of the precursors. The morphology and physical properties of these laser-grown films have been studied by scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. Optical absorption spectra of films grown on fused quartz were measured as a function of substrate temperature. A substrate temperature of 350 K was found to be optimum for obtaining good film quality while precluding any effects due to the thermal decomposition of the precursors. The films have excellent dielectric properties as shown by I-V and C-V measurements. The details of AlN film growth using low-temperature gas-phase photolysis at 193 nm and the characterization of these laser grown films will be discussed.

Appearance of Indium Oxide Nanorods in MOCVD Growth

2006 ◽  
Vol 510-511 ◽  
pp. 146-149 ◽  
Author(s):  
Ju Hyun Myung ◽  
Hyoun Woo Kim ◽  
S.H. Shim
Keyword(s):  
Cross Section ◽  
Circular Cross Section ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mocvd Growth ◽  
Oxide Nanorods ◽  
Cubic Structure ◽  
Scanning Electron

We report on the first synthesis of nanosized In2O3 rods using the TEI as a precursor in the presence of oxygen. The samples were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy. XRD analysis revealed that the products are In2O3 phase with a tetragonal cubic structure. SEM analysis indicated that the obtained nanorods have a circular cross section and a diameter in the range of 50-150 nm.

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