GeSbTe

<p>GeSbTe (germanium-antimony-tellurium or GST) is a <a href="/facts/Phase-change_material/NDVVyXs3">phase-change material</a> from the group of <a href="/facts/Chalcogenide_glass/6Lug8YLy">chalcogenide glasses</a> used in rewritable <a href="/facts/Optical_disc/vjVDB1GH">optical discs</a> and <a href="/facts/Phase-change_memory/jeMTI5RI">phase-change memory</a> applications. Its recrystallization time is 20 nanoseconds, allowing <a href="/facts/Bitrate/ppUNMmVd">bitrates</a> of up to 35 <a href="/facts/Megabit/tR6WBEG3">Mbit</a>/s to be written and direct overwrite capability up to 106 cycles. It is suitable for land-groove recording formats. It is often used in <a href="/facts/DVD-RW/HAFThLD3">rewritable DVDs</a>. New phase-change memories are possible using <a href="/facts/Doping_(semiconductors)/WrGdtWnm">n-doped</a> GeSbTe <a href="/facts/Semiconductor/zFf3mGTE">semiconductor</a>. The <a href="/facts/Melting_point/MY0w0h0k">melting point</a> of the <a href="/facts/Alloy/I7w7WQWR">alloy</a> is about 600 °C (900 K) and the <a href="/facts/Crystallization/oCUUG80k">crystallization</a> temperature is between 100 and 150 °C.
</p><p>During writing, the material is erased, initialized into its <a href="/facts/Crystalline/e2R2mk3E">crystalline</a> state, with low-intensity laser irradiation. The material heats up to its crystallization temperature, but not its melting point, and crystallizes. The information is written at the crystalline phase, by heating spots of it with short (<10 ns), high-intensity <a href="/facts/Laser/jk6PTvvT">laser</a> pulses; the material melts locally and is quickly cooled, remaining in the <a href="/facts/Amorphous/YTIzmrR0">amorphous</a> phase. As the amorphous phase has lower <a href="/facts/Reflectivity/TT4sBwIw">reflectivity</a> than the crystalline phase, data can be recorded as dark spots on the crystalline background. Recently, novel liquid <a href="/facts/Organogermanium/KEBQDGLV">organogermanium</a> precursors, such as <a href="/facts/Isobutylgermane/jL6slpED">isobutylgermane</a> (IBGe) and tetrakis(dimethylamino)germane (TDMAGe) were developed and used in conjunction with the <a href="/facts/Metalorganics/WFv2Ypum">metalorganics</a> of <a href="/facts/Antimony/YsA7lVgT">antimony</a> and <a href="/facts/Tellurium/v7QvfIvS">tellurium</a>, such as tris-dimethylamino antimony (TDMASb) and di-isopropyl telluride (DIPTe) respectively, to grow GeSbTe and other <a href="/facts/Chalcogenide/GTXXbDoV">chalcogenide</a> films of very high purity by <a href="/facts/Metalorganic_chemical_vapor_deposition/Ldg0BICo">metalorganic chemical vapor deposition</a> (MOCVD). Dimethylamino germanium trichloride  (DMAGeC) is also reported as the chloride containing and superior dimethylaminogermanium precursor for Ge deposition by MOCVD.
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GeSbTe open-in-new

GeSbTe