Skip navigation
The Australian National University

Research facilities

ANU has a wide range of experimental facilities of relevance to solar research, including dedicated facilities within the Research School of Engineering, and others operated and managed elsewhere on the campus. Access to the latter is subject to negotiation with the relevant areas.

Following research groups have relevant facilities:

Photoluminescence Imaging


BTimaging LIS-R1 PL imaging equipment is available for all researchers at CECS. It can create rapid, high definition (1 mega-pixel) images of the band-to-band PL emission from silicon wafers, and the excess carrier lifetime.

Solar simulator (IV tester)


A solar simulator (IV tester) is being set up at CECS. The Solar Simulator (IV tester) measures the current-voltage characteristics of a solar cell.  The characteristics can be measured over a temperature range of 0-60 degrees, and either in the dark or under one-sun illumination.  The illumination source is rated AAA in terms of uniformity, stability and spectrum over an area of 15 cm × 15 cm.

Two Varian deposition systems


These machines are thermal evaporators used for deposition of metals on the sample surface. The metal to be deposited is held in vacuum in a tungsten boat and is resistively heated. The surface to be coated is held on top of the boat and the chamber enclosing the metal source and the target (sample to be coated) is pumped down to a pressure of ~ 3-5 ×10-6 Torr. Evacuating the deposition chamber helps reduce contaminations and increases the mean free path of the metal vapors. The metal vapors are deposited on the sample (on the inner walls of the entire chamber) and the thickness is measured using a crystal monitor (the deposited thickness is calculated by measuring the frequency of vibration of the crystal).

Photolithography


The machine has three different sized chucks that can hold 2", 3" or 4" wafers. This machine is routinely used for patterning Si wafers for making slivers (lateral dimensions ~12 µm).

Furnaces


8 furnaces that can handle 4" wafers and 3 furnaces that can hold 2" wafers are currently operational. The furnaces capable of holding 4" wafers are used for P/B diffusions or for oxidation. The temperature can be varied between 200 °C and 1100 °C, but are usually operated between 700 °C and 1100 °C. The furnaces capable of holding 2" wafers are used for annealing. N2/O2/forming gas ambient can be used for annealing.  Temperature can be varied between 400 and 1100 °C. Some furnaces cannot be used for metals (to avoid cross-contamination).

Spin rinser


This machine is used for cleaning wafers. Cassettes holding 25 of 4" wafers can be cleaned at a time. There are 2 chambers, one for metals and one for samples free of any metals. The samples are rinsed with DI water and dried.

Fume cupboards


One fume cupboard is exclusively used to handle cyanides and 7 other fumehoods are available for handling acids and solvents.

2 Laser scribers (JPSA and Synova)


These machines are used for patterning Si wafers for making slivers. IR or green laser pulses are produced that scribe a pattern on a coating used for wafer protection and a layer of dielectric beneath it. Wet etching is then used to etch through the wafer along the pattern opened up in the dielectric by the scriber. The scribe depth can go up to 500 µm and the minimum lateral dimensions that can be patterned depend on how well the laser pulse is focused on to the wafer. Lateral scribe dimensions of ~ 5µm can be achieved. The Synova laser scriber has the capability to simultaneously dope the Si with P while etching.

3 dicing saws (ADT, DISCO and K & S)


These dicing saws are used for cutting Si or glass. Wafers with a maximum thickness ~1.6 mm can be cut with a lateral resolution of ~ 150 µm. The lateral resolution can be increased by choosing appropriate blades, but blades that can cut smaller lateral dimensions are usually brittle and can only be used for dicing thinner wafers. All machines are semi-automated.

Screen printer


Screen printing is used for depositing metal pastes on the semiconductor surface. The sample is then annealed to make electrical contact between the metal and the semiconductor. This is a labor intensive task (issues with cleaning for use of different metals, issues with alignment) and is not viable for laboratory studies. The metal pastes used usually have an expiry period of 3 months and additional solvents need to be used to be able to continue using the pastes. Features with minimum dimensions ~100 µm can be printed using this technique.

Roth & Rau AK 400 PECVD and RIE


The PECVD system has provision for silane, nitrous oxide and ammonia anc can be used for deposition of Si3N4, SiO2 and amorphous Si. The RIE machine is currently being tested for etch uniformity and resolution. The machine has provision for CF4 and H2 gas sources. The system has two power sources, microwave source for creating plasma and an RF source for biasing the substrate.

APCVD


The SierraTherm 5k6 atmospheric pressure chemical vapor deposition system essetailly is a 12' long beltfurnace, with a CVD injector head in the middle, the injector head sprays a mist of tetra-isopropyl-titanate (TPT) and water vapor on to samples passing on the belt below. Nitrogen gas sheets prevent the reactants mixing until they intercept the top of the passing samples where they mix hydrolysing the TPT creating TiO2 films. Parameters that can be modified to control the properties of the deposited film are belt speed, reactant / nitrogen carrier ratios, reactant / reactant ratios, total flow rate, and temperature. . Once the system has been calibrated and suitable reactant / reactant ratios have been calculated to control the thickness of the film the belt speed and total gas flow are adjusted. The temperature range of the APCVD can be controlled to between 100 and 500 °C, with the effect of changing the crystallographic structure of the TiO2 film and it optical properties.
This system is capable of depositing uniform TiO2 films between 20 and 200 nm thick with refractive index ranging from 1.9 - 2.5 depending on the deposition temperature. The system has also been modified to include forming gas in the CVD injector head.

LPCVD × 2: CVD-LPCVD and Tempress LPCVD


These two machines are used for depositing Si3N4 on wafers. The machines are usually operated at 775 °C with fixed flows for Ammonia and dichlorosilane, which results in a deposition rate of ~6 nm/min. The Tempress machine is a relatively new machine that is automated and safer to use.

Sliver plating

Filmetrics F20


Filmetrics F20 is used for characterizing thin films. Film thickness ranging from 150 Å to 50 µm can be measured. Refractive index and extinction coefficient can be measured for film thickness ranging between 1000 Å and 5 µm for wavelengths from 400 nm to 1000 nm.

Flash IV tester


Flash tester is used to measure the IV response of solar cells. The cell temperature is controlled using a Peltier cooler and can go upto a maximum of 70 °C. The flash intensity can be varied between 1 sun and a maximum of 100 suns.

Sinton lifetime testers


The equipment measures the effective carrier lifetime that can be used to deduce the bulk lifetime, metal contaminations (Fe/Cr) and the quality of surface passivation. All the software has been set up for Si. The machine can also be used as a backup for resistivity measurements.

Kelvin probe

Quicky solderer


This is a vapor phase soldering machine and is used for making metal interconnects on the solar cells. The metal to be soldered is deposited on the cell surface using a stencil and the cell is then placed inside the solder chamber. The chamber contains a Teflon type fluid, which can be heated up to temperatures of ~215 °C. The vapors surround the entire cell with metal pattern on its surface, raising its temperature and thus soldering. The equipment is easy to clean (rinsed with water). The equipment avoids exposure of samples to O2 and can handle six 50 mm×40 mm samples at a time.

Spot welding


Is used for soldering Cu wires to interconnect the solar cells.

Selective wave solderer (EBSO SPA 300-F)


This is a fully automated machine that is used to interconnect individual solar cells to produce a linear concentrator module.

Four point probe measurement

Spectral response unit

Unitemp RTA


The machine has 2 chambers, one intended for metals and the other chamber is RCA cleaned. The chambers can hold a maximum wafer area of 5"×5".The maximum temperature this machine can handle is 1000 °C (for 1 s). N2/forming gas/O2 ambient can be used while annealing.

Updated:  6 June 2012 / Responsible Officer:  JavaScript must be enabled to display this email address. / Page Contact:  JavaScript must be enabled to display this email address. / Powered by: Snorkel 1.4