Selective Area Chemical Vapor Deposition of Si[sub 1−x]Ge[sub x] Thin Film Alloys by the Alternating Cyclic Method: Experimental Data: I. Deposition Parameters

Soman, R; Reisman, Arnold; Temple, Dorota; Alberti, R.

doi:10.1149/1.1393445

Cited by 7 publications

(4 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The evolution of process parameters for selective deposition of Si 1Ϫx Ge x thin films, using the AC process has been described in the companion paper. 25 Once the conditions were established for selectively depositing epitaxial quality Si 1Ϫx Ge x films, the following process window was explored: SiCl 4 ϭ 99.75-97 standard cubic centimeters per minute (sccm), GeCl 4 ϭ 0.25-3 sccm, H 2 ϭ 10 standard liters per minute (slpm), Ar ϭ 10 slpm, p t ϭ 2.5 Torr, temperature ϭ 850-950ЊC, and deposition time ϭ 3.75-60 min. Note that, in the AC process employed, HCl is not used for nuclei removal.…”

Section: Methodsmentioning

confidence: 99%

Selective Area Chemical Vapor Deposition of Si[sub 1−x]Ge[sub x] Thin Film Alloys by the Alternating Cyclic Method: Experimental Data: II. Morphology and Composition as a Function of Deposition Parameters

Soman

Reisman

Temple

et al. 2000

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

The last few years have seen considerable advancement in SiGe technology due to the potential for achieving device speeds greater than those obtained with silicon only devices. 1-3 Si 1Ϫx Ge x heterostructures have found applications in fabricating heterojunction bipolar transistors (HBTs), 4-17 and in channel engineering, 18 as gate material, 19 and in contact resistance applications 20 in insulated gate field effect transistors (IGFETs). In order to fabricate such devices, excellent control over the morphology and composition of epitaxial Si 1Ϫx Ge x films is mandatory. For Si 1Ϫx Ge x films to be useful, they should be microscopically smooth and exhibit good crystalline quality.Si and Ge are completely miscible over the entire composition range. 5 Hence, they can be intermixed to form a stable alloy, Si 1Ϫx Ge x , where x represents the mole fraction of Ge in the alloy. However, the lattice constant of Si is about 4.2% smaller than that of Ge, leading to a number of practical difficulties in deposition of SiGe alloys for use in semiconductor applications. 21 In order to retain crystal perfection at low Ge compositions, e.g., less than 30 mol %, the Si 1Ϫx Ge x films need to adopt the smaller lattice constant of the host material without relaxing. This accommodation, known as strained layer epitaxy, induces compressive strain in the overlying film. Strained layer epitaxial films are stable only under a narrow range of conditions, dependent on the film's effective strain, which increases with increasing Ge composition and film thickness, and also depends on the temperature of subsequent treatment. Films with a high Ge content must be deposited at low temperatures to prevent relaxation, and they must be very thin if they are to be stable. 22,23 Band structure, optical properties, and the carrier mobility are determined by the homogeneous strain in the lattice structure. The homogeneous strain is, therefore, a key factor in determining the usefulness of the layers. The strain can relax by forming crystalline defects and/or three-dimensional growth, which degrade the electrical characteristics.The film thickness, t m , at which transition from smooth to rough morphology takes place, depends on the mole fraction of Ge in the Si 1Ϫx Ge x films and the temperature of deposition. The choice of temperature for deposition of Si 1Ϫx Ge x films requires the balancing of two competing temperature requirements. The atoms should have sufficient mobility to achieve good quality epitaxy. The mobility of atoms increases with increase in temperature. However, the transition from smooth to rough surface morphology, which tends to degrade morphological quality and which is needed for current device applications, is enhanced at a given film thickness at higher growth temperatures.In this paper, we investigate the effect of processing conditions such as deposition temperature, input gas phase composition, flow rates, and deposition time, on the resulting Si 1Ϫx Ge x film composition, morphology, and crystalline perfection, using the ...

show abstract

Section: Methodsmentioning

confidence: 99%

Selective Area Chemical Vapor Deposition of Si[sub 1−x]Ge[sub x] Thin Film Alloys by the Alternating Cyclic Method: Experimental Data: II. Morphology and Composition as a Function of Deposition Parameters

Soman

Reisman

Temple

et al. 2000

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

show abstract

“…An increase in the Ge precursor flow led to an expected increase in Ge content and an unexpected reduction of the growth rate. Ge incorporation was limited to ≤12%, unlike the full compositional tunability demonstrated for random Au-catalyzed growth of SiGe nanowires with silane and germane precursors. , Consistent with the work of Soman et al on thin film growth, contamination from adventitious Ge species on reactor surfaces makes reproducibility more challenging than for pure silicon growth, and in our case contamination results in growth of disordered nano- and microwire forests instead of vertical microwires. Improved reproducibility was achieved by alternating SiGe wire growths with pure Si growth, in effect keeping the reactor in a steady state.…”

Section: Introductionmentioning

confidence: 99%

Cu-Catalyzed Vapor–Liquid–Solid Growth of SiGe Microwire Arrays with Chlorosilane and Chlorogermane Precursors

Chen

Emmer

Aloni

et al. 2015

Crystal Growth & Design

View full text Add to dashboard Cite

Selected area Cu-catalyzed vapor−liquid−solid growth of SiGe microwires is achieved using chlorosilane and chlorogermane precursors. The composition can be tuned up to 12% Ge with a simultaneous decrease in the growth rate from 7 to 1 μm min −1 . Significant changes to the morphology were observed, including tapering and faceting on the sidewalls and along the lengths of the wires. Characterization of axial and radial cross sections with transmission electron microscopy revealed no evidence of defects at facet corners and edges, and the tapering is shown to be due to in situ removal of catalyst material during growth. X-ray diffraction and transmission electron microscopy reveal a Ge-rich crystal at the tip of the wires, strongly suggesting that the Ge incorporation is limited by the crystallization rate.

show abstract

“…Two recently published papers describing experimental work based on the present thermodynamic analysis support the conclusions arrived at herein. 12,13 The Alternating Cyclic (A.C.) Process for Selective Area Deposition of Si 1Ϫx Ge x The A.C. technique is based on the existence of an embedded disproportionation reaction within the framework of an overall hydrogen reduction process. 14,15 By simply pulsing the hydrogen on and off in the embedded disproportionation reaction process, at a predetermined frequency and at a predetermined on to off cycle ratio, the embedded disproportionation reaction can be suppressed or made dominant, causing deposition and etching to occur in a cyclic fash-ion, respectively.…”

mentioning

confidence: 99%

Selective Area Chemical Vapor Deposition of Si[sub 1−x]Ge[sub x] Thin Film Alloys by the Alternating Cyclic Method: A Thermodynamic Analysis. I. The System Si-Ge-Cl-H

Soman¹,

Reisman²,

Temple³

2000

J. Electrochem. Soc.

View full text Add to dashboard Cite

To investigate selective area chemical vapor deposition of Si 1Ϫx Ge x thin films by the alternating cyclic (A.C.) process, a thermodynamic analysis has been performed over extensive temperature, pressure, input gas ratio, and deposited solid composition ranges. In the A.C. approach Si 1Ϫx Ge x thin film deposition via the hydrogen reduction of SiCl 4 and GeCl 4 is followed cyclically by etching of spurious nuclei from mask regions via an embedded disproportionation reaction. The embedded disproportionation reaction between SiCl 4 , GeCl 4 , and the Si 1Ϫx Ge x nuclei is made dominant when the hydrogen flow is interrupted cyclically. The thermodynamic calculations have been carried out via the computer program, SOLGASMIX, which is based on the minimization of the system's Gibbs free energy, and also using a first principles approach as an integrity check. These calculations have indicated that selective area deposition of Si 1Ϫx Ge x thin films by the A.C. method is feasible. The analysis has also defined the parameter space in which to conduct the selective area deposition using the A.C. process.

show abstract

Selective Area Chemical Vapor Deposition of Si[sub 1−x]Ge[sub x] Thin Film Alloys by the Alternating Cyclic Method: Experimental Data: I. Deposition Parameters

Cited by 7 publications

References 30 publications

Selective Area Chemical Vapor Deposition of Si[sub 1−x]Ge[sub x] Thin Film Alloys by the Alternating Cyclic Method: Experimental Data: II. Morphology and Composition as a Function of Deposition Parameters

Selective Area Chemical Vapor Deposition of Si[sub 1−x]Ge[sub x] Thin Film Alloys by the Alternating Cyclic Method: Experimental Data: II. Morphology and Composition as a Function of Deposition Parameters

Cu-Catalyzed Vapor–Liquid–Solid Growth of SiGe Microwire Arrays with Chlorosilane and Chlorogermane Precursors

Selective Area Chemical Vapor Deposition of Si[sub 1−x]Ge[sub x] Thin Film Alloys by the Alternating Cyclic Method: A Thermodynamic Analysis. I. The System Si-Ge-Cl-H

Contact Info

Product

Resources

About