Effect of Thermal Ramping and Annealing Conditions on Defect Formation in Oxygen Implanted Silicon-On-Insulator Material

Krause, Stephen; Park, J.C.; Lee, J.D.; El-Ghor, M. K.; Roitman, P.

doi:10.1109/soi.1992.664804

Cited by 2 publications

(1 citation statement)

References 3 publications

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“…It has been shown that a significant supersaturation of oxygen can only occur during a fast ramping which in that case results in a high density of defects. 28 The third source of Si I is the formation of surface thermal oxide when the sample is annealed without a protective cap. The key factors here are the annealing temperature, time, and the concentra-tion of oxygen in the ambient.…”

Section: Effect Of Capping Layer On Formation Of the Boxmentioning

confidence: 99%

The Effects of Surface Capping during Annealing on the Microstructure of Ultrathin SIMOX Materials

Johnson

Tan

Anderson

et al. 2001

J. Electrochem. Soc.

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The effects of a protective capping layer on the microstructure of ultrathin separation by implantation of oxygen ͑SIMOX͒ materials formed by ion implantation were studied using transmission electron microscopy. A set of SIMOX wafers were implanted at 65 keV in a dose range of 1.5 to 7.0 ϫ 10 17 O ϩ /cm 2 followed by a high temperature ͑1350°C͒ annealing with and without a protective cap. The lowest dose to form a continuous buried oxide ͑BOX͒ layer without Si islands at 65 keV is 2.0 ϫ 10 17 O ϩ /cm 2 without a protective cap and 2.5 ϫ 10 17 O ϩ /cm 2 with a protective cap. Above 2.5 ϫ 10 17 O ϩ /cm 2 under both annealing conditions, the BOX layer formed continuously but with Si islands present. The uncapped samples show slightly lower density of Si islands. Oxygen from the annealing ambient can diffuse in the uncapped samples through the thin top Si layer, which helps the BOX layer grow laterally and lower the Si island density. The density of defects in the top Si layer is also slightly lower in the uncapped samples because of the ability of Si interstitials to incorporate into the surface and the effective annihilation of extended defects during the final annealing step. The top Si layers of the uncapped samples are thinner than those of the capped samples due to surface thermal oxidation.The development of high quality ultrathin silicon-on-insulator ͑SOI͒ substrates is essential for the emerging submicrometer technology and fully depleted applications. SOI substrates have many advantages over bulk Si substrates for isolation, process simplicity, for short channel device performance, and for applications involving low power, high speed, high temperature, and radiation hardness. [1][2][3][4][5] Of the several SOI technologies, the most advanced is the synthesis of a buried oxide ͑BOX͒ layer by the separation by implanted oxygen ͑SIMOX͒ technique. 6 Conventionally, SIMOX wafers are produced by implanting high dose high energy oxygen ions ͑1.8 ϫ 10 18 O ϩ /cm 2 , 200 keV͒ into Si wafers. This process is expensive because it requires a long implantation time. In addition, the wafers produced by this technology contain a relatively high density of threading dislocations in the top Si layers. In order to overcome these problems, the low dose SIMOX technique was introduced. However, the low dose BOX layer is inferior to that of the high dose SIMOX in terms of electrical characteristics and reliability. Recently, it has been shown that the integrity of thin BOXs can be improved by annealing in a highly oxidizing ambient. 7 The same method has also been used to successfully produce thin film SIMOX wafers through surface oxidation. 8,9 However, a high production cost is incurred from the additional processing steps.A direct and cost-effective way to reduce the thickness of the top Si layer and the BOX layer is to decrease both the implantation energy and the oxygen dose. Reducing the implantation energy decreases the spread of the implanted ions which makes it possible to form a continuous BOX layer at lower doses whic...

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Section: Effect Of Capping Layer On Formation Of the Boxmentioning

confidence: 99%

The Effects of Surface Capping during Annealing on the Microstructure of Ultrathin SIMOX Materials

Johnson

Tan

Anderson

et al. 2001

J. Electrochem. Soc.

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Role of Oxygen Precipitation Processes in Defect Formation and Evolution in Oxygen Implanted Silicon-on-Insulator Material

et al. 1992

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The role of precipitation processes in defect development in high temperature implanted single and multiple implant/anneal SIMOX was studied by transmission electron microscopy. The differences in defect type, density and location were compared. The dominant defects in single implanted and annealed material are pairs of narrow stacking faults (NSFs) at a density of ∼ 106 cm−2 while stacking fault pyramids (SFPs) at a similar density dominate multiple implant/anneal material. However, SFPs are confined to the buried oxide interface and thus the density of through-thickness defects is about two orders of magnitude lower in multiple implant (<104 cm−2) than in single implant material (∼106 cm−2). SFPs are formed from a collection of four NSFs pinned to residual oxide precipitates. This transformation is energetically possible only below a critical NSF length which is dictated by the relative location of the residual precipitates. In turn, the residual precipitate location is determined by the location of as-implanted defects on which SiO2 preferentially nucleates and grows. Thus, the synergistic interaction between precipitation and defect formation and evolution processes plays a key role in determining the final defect microstructure of SIMOX.

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Effect of Thermal Ramping and Annealing Conditions on Defect Formation in Oxygen Implanted Silicon-On-Insulator Material

Cited by 2 publications

References 3 publications

The Effects of Surface Capping during Annealing on the Microstructure of Ultrathin SIMOX Materials

The Effects of Surface Capping during Annealing on the Microstructure of Ultrathin SIMOX Materials

Role of Oxygen Precipitation Processes in Defect Formation and Evolution in Oxygen Implanted Silicon-on-Insulator Material

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