Effect of Annealing on the Structure of Buried SiO2 Layers Formed By Elevated Temperature High Dose Oxygen Implantation

1985 ◽  
Vol 53 ◽  
Author(s):  
S.J. Krause ◽  
C.O. Jung ◽  
S.R. Wilson ◽  
R.P. Lorigan ◽  
M.E. Burnham

ABSTRACTOxygen has been implanted into Si wafers at high doses and elevated temperatures to form a buried SiO2 layer for use in silicon-on-insulator (SOI) structures. Substrate heater temperatures have been varied (300, 400, 450 and 500°C) to determine the effect on the structure of the superficial Si layer through a processing cycle of implantation, annealing, and epitaxial growth. Transmission electron microscopy was used to characterize the structure of the superficial layer. The structure of the samples was examined after implantation, after annealing at 1150°C for 3 hours, and after growth of the epitaxial Si layer. There was a marked effect on the structure of the superficial Si layer due to varying substrate heater temperature during implantation. The single crystal structure of the superficial Si layer was preserved at all implantation temperatures from 300 to 500°C. At the highest heater temperature the superficial Si layer contained larger precipitates and fewer defects than did wafers implanted at lower temperatures. Annealing of the as-implanted wafers significantly reduced structural differences. All wafers had a region of large, amorphous 10 to 50 nm precipitates in the lower two-thirds of the superficial Si layer while in the upper third of the layer there were a few threading dislocations. In wafers implanted at lower temperatures the buried oxide grew at the top surface only. During epitaxial Si growth the buried oxide layer thinned and the precipitate region above and below the oxide layer thickened for all wafers. There were no significant structural differences of the epitaxial Si layer for wafers with different implantation temperatures. The epitaxial layer was high quality single crystal Si and contained a few threading dislocations. Overall, structural differences in the epitaxial Si layer due to differences in implantation temperature were minimal.

1990 ◽  
Vol 183 ◽  
Author(s):  
S. Visitserngtrakul ◽  
C. O. Jung ◽  
B. F. Cordts ◽  
P. Roitman ◽  
S. J. Krause

AbstractHigh resolution electron microscopy (HREM) has been used to study the atomic arrangement of defects formed during high-dose oxygen implantation of silicon-on-insulator material. The effect of implantation parameters of wafer temperature, dose, and current density were investigated. Wafer temperature had the largest effect on the type and character of the defects. Above the buried oxide layer in the top silicon layer, HREM revealed that microtwins and stacking faults were created during implantation from 350–450°C. From 450–550°C, stacking faults were longer and microtwinning was reduced. From 550–700°C, a new type of defect was observed which had lengths of 40 to 140 nm and consisted of several discontinuous stacking faults which were randomly spaced and separated by two to eight atomic layers. We have referred to them as “multiply faulted defects” (MFDs). Beneath the buried oxide layer in the substrate region, the defects observed included stacking faults and ( 113 ) defects. The results indicated that some parts of the ( 1131 defects can assume a cubic diamond structure created through a twin operation across (115) planes. Details of the structure and formation mechanisms of MFDs and other defects will be discussed.


Author(s):  
Ni Rushan ◽  
Lin Chenglu

It Is well known that a buried silicon nitride or silicon oxide layer in silicon can be formed by high dose >150 KeV nitrogen or oxygen implantation into single crystal silicon followed by high temperature annealing. This is one of the techniques to produce silicon-on-insulator (SOI) structures which is promising for a variety of potential application in VLSI, high-voltage devices, high density CMOS circuits and possibly 3-dimensional integration, etc. The main concern is how to produce a buried dielective layer with good insulating properties and with a high quality single crystal silicon overlayer on it.In this paper the microstructures of buriea silicon nitride and silicon oxide layer of the SOI materials formed by N+ or O+ implantation in single-crystal silicon are studied oy means of cross-sectional transmission electron microscopy (XTEM) and infrared (IR) absorption measurements.


1987 ◽  
Vol 107 ◽  
Author(s):  
S.J. Krause ◽  
C.O. Jung ◽  
T.S. Ravi ◽  
S.R. Wilson ◽  
D.E. Burke

AbstractThe formation and structure of defects and precipitates in high-dose oxygen implanted silicon-on-insulator material was directly studied by weak beam and high resolution electron microscopy. In as-implanted material, the edge of the oxygen implant profile contained 1.5 nm diameter precipitates at a density of 1019 cm2. Defects, including micrctwins, stacking faults, and (311) defects, were present in as-implanted material but no threading or loop dislocations were observed. This suggests that threading dislocations are formed in the thermal ramping and annealing cycle. In material annealed for different times and temperatures precipitate size was much more dependent on peak temperature rather than time-at-temperature indicating that oxygen diffusion distance is less important than thermodynamic factors in controlling precipitate size. Annealing from 1150°C to 1250°C produced threading dislocations and possible dislocation dipoles which extended through the superficial layer. Transient annealing of very low dose oxygen implanted Si produced loop and threading dislocations. This suggests that a high heating rate during precipitation will generate excess Si interstitials at a rate high enough to create high stresses at precipitates and form dislocations. A qualitative model for dislocation formation is proposed and processing conditions for reducing dislocation density are suggested.


Author(s):  
N. Lewis ◽  
E. L. Hall ◽  
A. Mogro-Campero ◽  
R. P. Love

The formation of buried oxide structures in single crystal silicon by high-dose oxygen ion implantation has received considerable attention recently for applications in advanced electronic device fabrication. This process is performed in a vacuum, and under the proper implantation conditions results in a silicon-on-insulator (SOI) structure with a top single crystal silicon layer on an amorphous silicon dioxide layer. The top Si layer has the same orientation as the silicon substrate. The quality of the outermost portion of the Si top layer is important in device fabrication since it either can be used directly to build devices, or epitaxial Si may be grown on this layer. Therefore, careful characterization of the results of the ion implantation process is essential.


1991 ◽  
Vol 6 (4) ◽  
pp. 792-795 ◽  
Author(s):  
Supapan Visitserngtrakul ◽  
Stephen J. Krause ◽  
John C. Barry

Conventional and high resolution electron microscopy (HREM) were used to study the structure of {113} defects in high-dose oxygen implanted silicon. The defects are created with a density of 1011 cm−2 below the buried oxide layer in the substrate region. The HREM images of the {113} defects are similar to the ribbon-like defects in bulk silicon. It is proposed that there is a third possible structure of the defects, in addition to coesite and/or hexagonal structures. Portions of some defects exhibit the original cubic diamond structure which is twinned across {115} planes. The atomic model shows that the {115} interface is a coherent interface with alternating five- and seven-membered rings and no dangling bonds.


1989 ◽  
Vol 163 ◽  
Author(s):  
S. Visitserngtrakul ◽  
J. Barry ◽  
S. Krause

AbstractConventional and high resolution electron microscopy (HREM) were used to study the structure of the {113} defects in high-dose oxygen implanted silicon. The defects are created with a density of 1011 cm-2 below the buried oxide layer in the substrate region. The {113} defects are similar to the ribbon-like defects in bulk silicon. Our HREM observations show that two crystalline phases are present in the defect. Portions of the defects exhibit the original cubic diamond structure which is twinned across {115} planes. The atomic model shows that the {115} interface is a coherent interface with alternating five- and seven-membered rings and no dangling bonds.


1987 ◽  
Vol 93 ◽  
Author(s):  
A. H. van Ommen ◽  
H. J. Ligthart ◽  
J. Politiek ◽  
M. P. A. Viegers

ABSTRACTHigh quality Silicon-On-Insulator, with a dislocation density lower than 105cm−2, has been formed by high temperature annealing of high-dose oxygen implanted silicon. In the as-implanted state, oxygen was found to form precipitates in the top silicon film. In the upper region these precipitates were found to order into a superlattice of simple cubic symmetry. Near the interface with the buried oxide film the precipitates are larger and no ordering occurs in that region. Contrary to implants without precipitate ordering where dislocations are observed across the entire layer thickness of the top silicon film, dislocations are now only found near the buried oxide. The precipitate ordering appears to prevent the dislocations to climb to the surface. High temperature annealing results in precipitate growth in this region whereas they dissolve elsewhere. These growing precipitates pin the dislocations and elimination of precipitates and dislocations occurs simultaneously, resulting in good quality SOI material.


2003 ◽  
Vol 83 (15) ◽  
pp. 3162-3164 ◽  
Author(s):  
Yasuhiko Ishikawa ◽  
Yasuhiro Imai ◽  
Hiroya Ikeda ◽  
Michiharu Tabe

1991 ◽  
Vol 235 ◽  
Author(s):  
M. K. El-Ghor ◽  
K. A. Joyner ◽  
H. H. Hosack

ABSTRACTWe have investigated the effect of the presence of oxide particles on the surface of silicon wafers during high energy, high dose implantation of oxygen into silicon. It was found that for single implants with doses of 1.5 × 1018/cm2 or 1.8 × 1018/cm2, such particles produce a non-continuous buried oxide layer in the as-implanted condition as well as after annealing. Etching results showed that no defects, which formed etchable paths through the buried oxide, were produced for particles with diameters 0.43 um or below for the lower dose and 0.53 um for the higher dose.


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