Experimental Investigation of the Impact of Implanted Phosphorus Dose and Anneal on Dopant Diffusion and Activation in Germanium

2008 ◽  
Vol 1070 ◽  
Author(s):  
Vincent Mazzocchi ◽  
Stéphane Koffel ◽  
Cyrille Le Royer ◽  
Pascal Scheiblin ◽  
Jean-Paul Barnes ◽  
...  
Keyword(s):  
Semiconductor Industry ◽  
Doping Profile ◽  
Dopant Diffusion ◽  
Activation Temperature ◽  
Cross Sectional ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Activation Level ◽  
Induced Defects ◽  
The Impact

ABSTRACTGermanium has regained attention in the semiconductor industry for MOSFET application because of the higher mobility of carriers – two times higher mobility for electrons and four times for holes – as compared to silicon. In the opposite of the Silicon, the major issue with Germanium is to limit the n-dopant diffusion. Usual n-dopants (Phosphorus and Arsenic for example) are not electrically activated at an acceptable level without a large diffusion of the doping profile and a substantial dose loss. In this work, we have studied the influence of low energy and dose implant (15KeV to 40KeV @ 8E13 to 1E15at.cm−2) and low temperature anneal (515°C to 600°C) on diffusion, exodiffusion and activation of the phosphorus dopant into Germanium. The annealing steps were made in RTP furnace, the chemical profile and electrically active profiles were extracted by using Secondary-Ion-Mass Spectroscopy (SIMS) and sheet resistance measurement (Rs). To investigate the implantation-induced defects in depth, cross-sectional micrographs were made by using Transmission Electron Microscopy (TEM). Experimental results show that we achieved an efficient activation level by tuning both dose implant and anneal temperature, limiting the exodiffusion with pratically no diffusion of the dopant. We also show that very abrupt profile can be achieved with appropriate implant and thermal annealing conditions. To limit the leakage current in devices, we suppose we have to limit the defects generated during the implantation. Specially for dopant activation temperature anneal below 550°C, we have shown and observed by cross-sectional micrograph that the defects are totally removed by addition of a pre step of annealing at 400°C.

Heteroep1Taxial Nucleation and Structural Properties of MBE GaAs on Recessed Si: Etching Implications.

1989 ◽  
Vol 145 ◽  
Author(s):  
Jo De Boeck ◽  
Jiben Liang ◽  
Jan Vanhellemont ◽  
Kristin Deneffe ◽  
Chris Van Hoof ◽  
...  
Keyword(s):  
Growth Front ◽  
Gaas Layer ◽  
Si Substrate ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Device Integration ◽  
Dry Etch ◽  
Induced Defects ◽  
The Impact ◽  
Facet Formation

AbstractGaAs is grown embedded in pre-etched wells in the Si substrate. HNO3:HF, KOH:H2O and a dry etch technique are used as alternatives to form the wells. Cross-sectional SEM views of AlGaAs/GaAs heterostructures reveal the growth front and facet formation for the different sidewall geometries. Transmission electron microscopy is used to study epilayer degradation in relation to the substrate damage and the presence of edge induced defects in the GaAs. Cathodoluminescence reveals the uniformity of strain present in the GaAs layer embedded in the wet etched well. The impact of the different etching techniques on device integration is briefly discussed.

Transmission Electron Microscopy Observation of 11MEV B5+ Ion Irradiation in Bi2Sr2CaCu2O7-x Single Crystal

1999 ◽  
Vol 5 (S2) ◽  
pp. 758-759
Author(s):  
W.L. Zhou ◽  
Y. Sasaki ◽  
Y. Ikuhara ◽  
C.J.O’Connor
Keyword(s):  
Single Crystal ◽  
Ion Irradiation ◽  
Target Material ◽  
Heavy Ion ◽  
Zone Melting ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Different Types ◽  
Induced Defects ◽  
Irradiation Induced Defects

Artificial defects generated by ion irradiation have been considered an efficient method to enhance the critical current density in superconducting materials. The mechanism of producing defects as flux pining centers is still an important issue since the efficiency of irradiation-induced defects in flux pinning strongly depends on their microstructures. Different types of defects have been found in heavy ion irradiation. However, there are few results that show light ion irradiation due to the target material selected, the type of light ion and energy, and the incident ion angle. Another factor is the difficulty of cross-sectional sample preparation. In this paper, a single crystal Bi2Sr2CaCu2O7-x with 11 MeV B5+ ion irradiation was observed by transmission electron microscope (TEM) from both plan and cross-sectional view.The Bi2Sr2CaCu2O7-x single crystals used for ion irradiation were prepared using the floating-zone melting method. The crystals were cleaved into thin sheets of about 20 μm thickness along the a-b plane and cut to about 2mmx2mm size.

Characterization of Structure and Mechanical Properties of MoSi2-SiC Nanolayer Composites

1993 ◽  
Vol 322 ◽  
Author(s):  
H. Kung ◽  
T. R. Jervis ◽  
J-P. Hirvonen ◽  
M. Nastasi ◽  
T. E. Mitchell
Keyword(s):  
Mechanical Properties ◽  
Structural Changes ◽  
Crystallization Process ◽  
Mechanical Response ◽  
Cross Sectional ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Layer Structures ◽  
Amorphous Structures

AbstractA systematic study of the structure-mechanical properties relationship is reported for MoSi2-SiC nanolayer composites. Alternating layers of MoSi2 and SiC were synthesized by DCmagnetron and if-diode sputtering, respectively. Cross-sectional transmission electron microscopy was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: crystallization and phase transformation of MoSi2, crystallization of SiC, and spheroidization of the layer structures. Nanoindentation was employed to characterize the mechanical response as a function of the structural changes. As-sputtered material exhibits amorphous structures in both types of layers and has a hardness of 11GPa and a modulus of 217GPa. Subsequent heat treatment induces crystallization of MoSi2 to form the C40 structure at 500°C and SiC to form the a structure at 700°C. The crystallization process is directly responsible for the hardness and modulus increase in the multilayers. A hardness of 24GPa and a modulus of 340GPa can be achieved through crystallizing both MoSi2 and SiC layers. Annealing at 900°C for 2h causes the transformation of MoSi2 into the Cllb structure, as well as spheroidization of the layering to form a nanocrystalline equiaxed microstructure. A slight degradation in hardness but not in modulus is observed accompanying the layer break-down.

Transmission electron microscopy of semiconductor devices

1986 ◽  
Vol 44 ◽  
pp. 722-723
Author(s):  
J. M. Brown
Keyword(s):  
Electron Microscopy ◽  
Cross Sections ◽  
New Technologies ◽  
Semiconductor Device ◽  
Semiconductor Industry ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Silicon Device ◽  
Design And Manufacture ◽  
Preparation Techniques

The search for further miniaturization in the semiconductor industry has resulted in the reduction in the dimensions of devices to a size which can no longer be effectively seen by the conventional methods of light microscopy. The use of both transmission and scanning electron microscopy in the field of silicon device characterization has now become an essential ingredient of the design and manufacture of new technologies. It is often the only way in which a device designer can know for certain whether the manufacturing process is producing the required structure. Cross-sectional TEM has therefore become an integral part of both quality control and development.One of the most important areas which resulted in the increased importance of TEM in the semiconductor device field was the development of sample preparation techniques which enable cross-sections through layers of widely differing compositions that are found in the devices structures.

INTERMIXING OF ION-IMLANTED AlGaAs/GaAs SUPERLATTICES

1985 ◽  
Vol 56 ◽  
Author(s):  
J. Ralston ◽  
G.W. Wicks ◽  
L.F. Eastman ◽  
L. Rathbun ◽  
B.C. DeCooman ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Auger Spectroscopy ◽  
Annealing Process ◽  
Dislocation Loops ◽  
Dense Network ◽  
Cross Sectional ◽  
The Third ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Residual Damage

AbstractCross-sectional Transmission Electron Microscopy, Sputter-Auger spectroscopy, and Raman spectroscopy have been used to study intermixing and residual damage in annealed ion-implanted Al0.3Ga0.7As/GaAs superlattices. Several implant species were studied Nse, Si, Mg, Be). Three different regions can be distinguished in the annealed ionimplanted superlattice samples. The topmost region contains a dense network of stacking faults and microtwins, residual damage from an implantation-amorphized region which has recrystallized during annealing. In the second region, which is relatively defect-free, either total, or at least appreciable intermixing of the GaAs and Al0.3Ga0.7As layers occurs. For fixed annealing conditions, the degree of intermixing varies with the mass of the implanted species. The third region contains many small dislocation loops which form by the agglomeration of point defects during implantation or the subsequent annealing process. Raman spectroscopy is used to compare the degree of intermixing and residual damage between AlGaAs alloys generated by superlattice disordering and uniform “as-grown” alloys of the same composition which have undergone identical implant and anneal treatments.

The Mechanism of Epitaxial Si-Ge/Si Heterostructure Formation by Wet Oxidation of Amorphous Si-Ge Thin Films

1989 ◽  
Vol 160 ◽  
Author(s):  
S.M. Prokes ◽  
A.K. Rai ◽  
W.E. Carlos
Keyword(s):  
Electron Diffraction ◽  
Solid Phase ◽  
Native Oxide ◽  
Wet Oxidation ◽  
Cross Sectional ◽  
Plan View ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Spin Resonance ◽  
Amorphous Si

AbstractEpitaxial SiGe/Si heterostructures have been formed by wet oxidation from amorphous SiGe films deposited on Si(100). Amorphous SixGe1-x films were deposited at a vacuum of 10-7 Torr. The presence of an initial native oxide precluded solid phase epitaxy under standard annealing conditions, but epitaxy could be achieved by the use of wet oxidation. The samples were oxidized at 900°C for various times and examined in reflection electron diffraction, ellipsometry, cross-sectional and plan-view transmission electron diffraction, and electron spin resonance. The formation of the epitaxial layer and oxide has been examined, and an epitaxial growth model is suggested.

Growth Mechanisms of YBa2Cu3O7-δ Thin Films Post Annealed at a Low Oxygen Partial Pressure

1993 ◽  
Vol 312 ◽  
Author(s):  
S. Y. Hou ◽  
D. J. Werder ◽  
Julia M. Phillips ◽  
J. H. Marshall
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Early Stage ◽  
Growth Mechanisms ◽  
Low Oxygen ◽  
Cross Sectional ◽  
Annealing Conditions ◽  
Post Annealing ◽  
Transmission Electron

AbstractThe growth mechanism of YBa2Cu3O 7-= thin films grown by the BaF2 post annealing process at low oxygen partial pressure have been studied by transmission electron microscopy. Under the annealing conditions of po2 = 4 Torr and 700°C, BaCuO2 and Y2 Cu2O5 precipitates develop from stoichiometric film precursors of YBCO during annealing. A growth model is proposed based on the observations. In addition, early stage nucleation and growth of both c- and a-axis oriented grains at the substrate interface were observed in quench annealed cross-sectional samples. 90° [100] symmetrical boundaries form between the a- and c-axis oriented grains. The possible effects of these boundaries are discussed.

Investigation of the Interface Integrity of the Thermally Stable Wn/GaAs Schottky Contacts

1989 ◽  
Vol 148 ◽  
Author(s):  
J. Ding ◽  
B. Lee ◽  
K. M. Yu ◽  
R. Gronsky ◽  
J. Washburn
Keyword(s):  
Amorphous Structure ◽  
Schottky Contacts ◽  
Thermally Stable ◽  
Contact Interface ◽  
Interface Morphology ◽  
Cross Sectional ◽  
X Ray ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Morphology And Structure

ABSTRACTWNx,/GaAs Schottky contacts formed by reactive sputtering were found to be thermally stable up to an annealing temprature of ∼9400°C. The interface morphology and structure of this contact under high temperature annealing conditions ( > 700°C ) have been investigated by transmission electron microscopy (TEM) and x-ray diffractometry techniques. For the as-deposited samples, the thin film had an amorphous structure. After annealing at high temperatures, the amorphous phase transformed to α-W and W2N phases. However, the contact interface remained thermally stable up to 850°C. Cross-sectional TEM micrographs revealed that annealing at temperatures above 850°C resulted in the formation of ‘pockets’ beneath the interface. This phenomenon has been correlated with the electrical properties of the contacts, e. g., an enhancement of the barrier height of the contact. Comparisons between the interface morphology of this system and other refractory metal nitride contacts (e. g., TiN/GaAs) are also presented.

Application of Cross-Sectional Transmission Electron Microscopy to the Characterization of Ion-Implanted Semiconductors

1985 ◽  
Vol 43 ◽  
pp. 292-295
Author(s):  
T. Sands
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Defect Formation ◽  
Defect Characterization ◽  
Cross Sectional ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Dopant Profile ◽  
The Many

Direct implantation of dopant ions is the most precise method for obtaining a desired dopant profile in a semiconductor substrate. However, in order to achieve satisfactory electrical properties, lattice defects introduced by the energetic dopant ions and by the subsequent annealing process must be confined or eliminated. Because of the many parameters which can be varied during implantation and annealing, it is not generally feasible to survey all conditions. Consequently, the most efficient approach is to understand the mechanisms of defect formation and annealing so that guidelines for choosing a set of implantation/annealing conditions can be determined.Since implantation depths are usually much less than one micron, suitable defect characterization techniques must demonstrate high spatial resolution. Cross-sectional transmission electron microscopy (XTEM) is one such technique. With a resolution (lateral and depth) of ∼0.2nm, the atomic structure of implantation-related defects is accessible.

THE DEFECT STRUCTURE OF ION-IMPLANTED AlxGa1−xAs/GaAs SUPERLATFICES

1985 ◽  
Vol 56 ◽  
Author(s):  
B.C. DE COOMAN ◽  
C.B. CARTER ◽  
J. RALSTON ◽  
G.W. WICKS ◽  
L.F. EASTMAN
Keyword(s):  
Electron Microscopy ◽  
Point Defects ◽  
Strain Field ◽  
Defect Structure ◽  
Extended Defects ◽  
Cross Sectional ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Residual Damage ◽  
Ion Implanted

AbstractCross-sectional transmission electron microscopy (XTEM) has been used to study the defect structure and intermixing of ion-implanted and annealed AlxGa1−xAs/GaAs superlattices. The results show clearly that the layer intermixing depends on mass and energy of the implanted species and the annealing conditions. The temperature and duration of annealing determines mainly the amount of residual damage. In addition it was observed that in all cases the point-defects agglomeration was influenced by the strain field present at the layer interfaces; extended defects nucleate preferentially in the GaAs layers.

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