Experiment

Hicari Experiment was performed on board the JEM "Kibo"

"Growth of Homogeneous SiGe Crystals in Microgravity by the TLZ method" (Hicari Exp.) was performed using a Gradient Heating Furnace (GHF) on board the JEM "Kibo".

In the Hicari Exp., a new crystal growth method named the Traveling Liquidus Zone (TLZ) method which JAXA invented for homogeneous semiconductor alloy crystal growth will be evaluated. Homogeneous Si_0.5Ge_0.5 crystals grown in microgravity conditions will offer basic data for growing large high quality crystals.

A cylindrical SiGe sample is heated by GHF heaters at a temperature gradient of about 10℃/cm and a germanium rich melt zone is formed. A SiGe crystal will be grown by controlling the growth interface temperature. Homogeneous composition will be obtained when the growth rate and the heater traveling rate are synchronized.

Sample cartridges containing a SiGe crystal and the GHF have already been transported to the ISS by the HTV2 "KOUNOTORI2". Since GHF check out experiments were completed, the first Hicari experiment started on 27th of Feb. 2013.

Totally four crystal growth experiments will be performed in the Hicari experiment. Second, third and fourth experiments will be carried out after analyzing the composition of the first SiGe experiment sample and reflecting the results to growth conditions of the three experiments.

Obtained data will be utilized for growing large homogeneous alloy crystals on the ground. SiGe crystals are promising as substrates of electronic devices superior to silicon. High mobility and low energy consumption electronic devices are expected using SiGe.

(PI: Kyoichi Kinoshita, Senior Researcher, JAXA)

*All times are Japan Standard Time (JST)