Germanium (Ge) Target Sputtering Guide

Version 1.0 | For Direct Download & Lab Use

1. Introduction & Material Overview

Germanium (Ge, atomic number 32) is a brittle, grayish-white metalloid semiconductor with excellent infrared transparency, high electron mobility, and good thermal stability. High-purity Ge sputtering targets (typically 99.99% (4N) to 99.999% (5N)) are widely used in PVD magnetron sputtering for depositing high-quality thin films in semiconductors, IR optics, photovoltaics, and phase-change memory devices.

Key Ge Target Properties

• Purity: 4N–5N (99.99–99.999%)

• Density: ≥5.32 g/cm³

• Typical Forms: Planar disk (Ø1–21 inch), thickness 1–10 mm

• Bonding: Optional Cu/Ti backing plate for heat dissipation

• Thermal Sensitivity: Low thermal shock resistance; prone to cracking at rapid heating/cooling

2. Pre-Sputtering Preparation

2.1 Target Handling & Installation

• Wear powder-free gloves, avoid direct skin contact with target surface.

• Clean target surface with isopropyl alcohol (IPA) and dry with pure nitrogen.

• Mount target firmly to the cathode; ensure good thermal contact if bonded.

• Seal chamber carefully; check for leaks.

2.2 Substrate Preparation

• Clean substrates (Si, glass, sapphire, etc.) via standard process:

1. Ultrasonic bath in acetone → 5 min

2. Ultrasonic bath in IPA → 5 min

3. Rinse with deionized water

4. Dry with N₂ gas

• Load into chamber; set target-to-substrate distance (10–15 cm typical).

2.3 Chamber & Vacuum Setup

• Pump down to base pressure ≤ 5×10⁻⁶ Torr (≤6.7×10⁻⁴ Pa).

• Leak test: ensure pressure rise rate < 1×10⁻⁵ Torr/h.

• Purge chamber with Ar gas 1–2 times if needed.

3. Standard Sputtering Parameters (DC/RF Magnetron)

3.1 Common Process Gases

• Main gas: High-purity Argon (Ar, 99.999%)

• Optional: H₂ (5–10% vol) for reducing oxidation; O₂ for GeOₓ films

3.2 Recommended Deposition Parameters