Indium In Evaporation Process Notes

Indium is a post-transition metal with properties similar to gallium. It is soft and metallic-gray in color. It has a density of 7.3 g/cc, a melting point of 157°C, and a vapor pressure of 10^-4 Torr at 742°C. One of its notable characteristics is its ability to cling to glass and other similar surfaces. Indium compounds are evaporated under vacuum to form thin films in the production of electronics and photovoltaic cells. Pure indium is utilized as a film layer in semiconductors.

Indium In Specifications

Material Type	Indium
Symbol	In
Atomic Weight	114.818
Atomic Number	49
Color/Appearance	Silvery Lustrous Gray, Metallic
Thermal Conductivity	82 W/m.K
Melting Point (°C)	157
Coefficient of Thermal Expansion	32.1 x 10-6/K
Theoretical Density (g/cc)	7.3
Sputter	DC

Type of Bond	Elastomer
Z Ratio	0.841
E-Beam	Excellent
Thermal Evaporation Techniques	Boat: W, Mo Basket: W Crucible: Gr, Al₂O₃
E-Beam Crucible Liner Material	FABMATE^®, Graphite, Molybdenum
Temp. (°C) for Given Vap. Press. (Torr)	10^-8: 487 10^-6: 597 10^-4: 742
Comments	Wets W and Cu. Use Mo liner. Low Melting Point materials not ideal for sputtering.

Thermal Evaporation of Indium (In)

When depositing any material in a vacuum system, there should be a lot of consideration taken upfront. Indium is not particularly problematic; however, any residual indium in the system will vaporize if it reaches a high enough temperature during subsequent deposition runs. It is recommended to use adequate foil shielding which can be removed after deposition is complete.

Indium can be thermally evaporated out of a tungsten basket heater with an aluminum oxide crucible, such as our EVB8B3030W and EVC9AO. Overspray can be limited to some degree by reducing the amount of material loaded in the crucible. Crucibles should be stored in a cool, dry place and always handled with gloves or forceps.

E-beam Evaporation of Indium (In)

Indium can be e-beam evaporated from a FABMATE^®, graphite, or molybdenum crucible liner and is rated excellent for e-beam evaporation. A key process note is to consider the fill volume in the e-beam application because we find that the melt level of a material in a crucible directly affects the success of the crucible liner. Overfilling the crucible will cause the material to spill over and create an electrical short between the liner and the hearth. The outcome is cracking in the crucible. This is the most common cause of crucible liner failure. Placing too little material in the crucible or allowing the melt level to get too low can be detrimental to the process as well. When the melt level is below 30%, the e-beam is likely to strike the bottom or walls of the crucible which immediately results in breakage. Our recommendation is to fill the crucible between 2/3 and 3/4 full to prevent these difficulties.

Crucible liners should be stored in a cool, dry place and always handled with gloves or forceps.

E-beam Crucible Liner Fill Rate Calculator

Instructions for use:
Input the Crucible Liner Volume, Select Material (if not available in menu, manually input Material Density in g/cm³), and input fill rate %.

KJLC recommends a fill rate between 67-75%. Overfilling the crucible will cause the material to spill over and create an electrical short between the liner and the hearth causing the crucible to crack. Placing too little material in the crucible or allowing the melt level to get too low can be detrimental to the process as well. When the melt level is below 30%, the e-beam is likely to strike the bottom or walls of the crucible which immediately results in breakage.

The fill rate above assumes that the material is fully melted and does not take into account packing density. It should be noted that the crucible liner may need to be loaded multiple times, pre-melted, and topped off in order to achieve the final desired melt level/fill rate. When loading the crucible, do not load more than 80% of the height of the crucible liner.

This calculator is for estimation purposes only.

Crucible Liner Volume (in cc):

Material:

- or -
Density of the material in g/cm³:

Fill Rate %:

Result

See highlighted results that match your result in the table below.

Material Needed to Deposit a 1 Micron Film Calculator

Instructions for use:
Select source type, input distance from source to substrate and Select Material (if not available in menu, manually input Material Density in kg/m³).

This calculator is for estimation purposes only. The estimated mass is that needed to produce a desired film thickness (1 micron in this case) on a flat substrate at a point directly above the source, accounting for the approximate plume distribution of the selected source type. It does not account for any expected nonuniformity in thickness over a larger substrate area. More complex geometries, e.g. those with offset and/or tilted sources, may have higher material requirements. The estimated mass is for the film deposition only; additional margin should be included to account for loss during ramp-up, burn-in, stabilisation and ramp-down.

Source:

Distance of source to substrate (in cm):

Material:

- or -
Density of the material in kg/m³:

Multiplier:

Mass for 1 micron layer

Indium In Evaporation Process Notes

Indium In Specifications

Z-Factors

Thermal Evaporation of Indium (In)

E-beam Evaporation of Indium (In)