Consisting of aluminum (Al) and silicon (Si), used primarily in the preparation of functional thin films by magnetron sputtering (PVD) and electron beam deposition processes.

Their unique low resistivity, anti-electromigration properties, and excellent mechanical properties have made them important applications in semiconductor interconnects, solar cells, display technology, and in other fields.

Aluminum-silicon targets play an important role in conventional semiconductors and newly emerging flexible electronics due to their advantages such as low resistivity, anti-electromigration, and process compatibility.

With increasing requirements for heterogeneous integration, miniaturization, and low-temperature manufacturing, high purity and composites will be the technological focus.

1. Characteristics

1) Low Resistivity and High Conductivity

・Aluminum-silicon alloys (e.g., Al-1%Si) have a low resistivity (~3.0 μΩ-cm) close to that of pure aluminum, making them suitable for highly conductive films.

・The addition of Silicon (usually 1-2 wt%) suppresses electromigration and improves the reliability of wiring.

2) Excellent electromigration prevention properties

・Silicon can sandwich aluminum grain boundaries at the atomic level, suppressing the diffusion of metal atoms at high temperatures and extending  device life (more than 10 times longer than the interconnection life of pure aluminum).

3) Good adhesion and mechanical properties

・The film conforms to the thermal expansion coefficient of SiO₂/Si substrates, reducing film stress cracking.

・Hardness (HV30-50) is higher than that of pure aluminum, making it suitable for coating flexible display board.

4) High purity and process compatibility

・Semiconductor grade Al-Si target purity ≥99.999% (5N), controlled Fe, Cu and other impurities less than 5ppm.

・Good low-temperature deposition performance (can be less than 150°C), compatible with organic substrates (PI films, etc.).

5) Adjustable Si content

・Conventional ratio: Al-1%Si (semiconductor wiring), Al-2%Si (display electrode)

・High Si content (Al-10%Si) can be used for special optical coatings.

2. Main Applications

1) Semiconductor integrated circuits

・Metal interconnect layer: Used in Al interconnect technology for processes 0.35 µm and above (memory chips, etc.).

・Bonding pads: As conductive connection layer between chips and packages.

2) Flat panel display technology

・TFT-LCD source/drain electrodes: Replaced by pure Al to reduce hillock defects.

・Touch sensor: Composite conductive layer with ITO (reduces square resistance).

3) Solar Cells

・ Silicon heterojunction (HJT) cell: Transparent conductive oxide (TCO) in amorphous silicon layer as bottom electrode.

・Thin film cell backside reflective layer: Improves light uptake efficiency.

4) Packaging and micro-electromechanical systems (MEMS)

・Wafer-level packaging: Re-Direction Layer (RDL) metallization.

・MEMS cantilever beam structure:　Provide both electrical conductivity and mechanical support.

5) New Application Fields

・Flexible electronics: Preparation of bendable conductive circuits on PET/PI substrates.

・3D printing conductive inks: electronics printing with nano Al-Si particles.

3. latest development trends

・Ultra-high purity Al-Si target: For sub-3nm advanced packages with purity of 99.9995% or higher (6N).

・Composite alloying:    Develop Al-Si-X (X=Cu, Ti, Nd) for high temperature stability.

・Low temperature process:  Meet the needs of temperature-sensitive devices such as OLEDs (<100°C deposition).