Evolution and Future Trends of SIMOX Material

Abstract

Oxygen-implanted silicon-on-insulator (SOI) material, or SIMOX (separation by implantation of oxygen), is another chapter in the continuing development of new material technologies for use by the semiconductor industry. Building integrated circuits (ICs) in a thin layer of crystalline silicon on a layer of silicon oxide on a silicon substrate has benefits for radiationhard, high-temperature, high-speed, low-voltage, and low-power operation, and for future device designs. Historically the first interest in SIMOX was for radiation-hard electronics for space, but the major application of interest currently is low-power, high-speed, portable electronics. Silicon-on-insulator also avoids the disadvantage of a completely different substrate such as sapphire or gallium arsenide. Formation of a buried-oxide (BOX) layer by high-energy, high-dose, oxygen ion implantation has the advantage that the ion-implant dose can be made extremely precise and extremely uniform. However the silicon and oxide layers are highly damaged after the implant, so high-temperature annealing sequences are required to restore devicequality material. In fact SIMOX process development necessitated the development of new technologies for high-dose implantation and high-temperature annealing.

Silicon substrates with buried distributed Bragg reflectors for resonant cavity-enhanced optoelectronics

“…Early problems inherent in the SIMOX process were large defect densities in the SOI layer due to implantation damage from the high energies and large implant doses. The high-dose implant of oxygen in Si causes threading defects (TD), which can be detrimental to device performance [11]. A major drawback to SIMOX is the depth limitation of the oxygen implant which correspondingly limits the thickness of the SOI layer ( 0.3 m).…”

Damage accumulation in neon implanted silicon

“…23,24 Oxygen implantation has been studied for the development of Si-on-insulator substrates for Si-CMOS ͑complementary metal-oxide semiconductor͒ technology. 25,26 This process, known as separation by implanted oxygen ͑SIMOX͒, is already well developed and commercialized in Si-based SOI wafers. Implantation of Si or O at elevated temperatures in silicon leads to the formation of two distinct layers: a dislocation free near-surface layer and a layer of interstitial type defects ͑dislocation loops, stacking faults, ͕311͖͒ located close to the region of ions' end of range.…”

Damage accumulation in Si during high-dose self-ion implantation

“…Despite these advances, it is notable that reconciliation of high temperature diffusion data with defect mobilities deduced from low temperature irradiation experiments remains an unsolved problem. [2][3][4] For most ion implantations, however, the mobilities and interactions of isolated defects are less crucial for understanding the damage state during annealing than are the properties and structures of point defect clusters. This is a consequence of most implantations being performed with heavy ions, which produce defects in high concentrations in energetic displacement cascades.…”