Material Properties and Applications of Indium Phosphide (InP)
Indium Phosphide (InP) is a compound semiconductor material of III-V group. This material has a wide band gap and a high electron mobility.
• Band Gap : 1.35 eV (300K) (1.2 times that of Si)
• Electron Mobility : 5,400 cm2/Vs (300K) (3.6 times that of Si)
Also, this material has large lattice constant of 5.8687 A. Therefore, InP-based alloys such as InGaAs, AlInAs, InGaAsP and AlGaInAs are grown on the InP substrate without lattice mismatches.
One of the applications of InP is photonic devices including laser diodes (LDs), photodiodes and waveguides. InP-based photonic devices have contributed to high-speed data transfer with less energy consumption at data centers.
Another application of InP is radio-frequency (RF) and microwave devices including power amplifiers. Low-noise, high-speed and low-DC power consumption devices are manufactured using InP substrates for military and telecommunication.
InP Pillar Etching with Vertical Sidewalls
InP pillar structures are used for various applications such as laser diodes and solar cells. There are top-down and bottom-up approaches to fabricate the nanopillar structures. The top-down approach using plasma etching technology offers uniform and precisely controlled structures. However, insufficient understanding of InP plasma etch chemistry causes pillar profile with rounded sidewalls. The rounded sidewalls are not preferable for laser diode fabrication because they deteriorate optical properties of light extraction and absorption. Therefore, there are process challenges in sidewall angle control as well as surface roughness control (RMS roughness) on InP etching.
To provide a process solution of InP pillar etching, Samco has developed etch recipes with optimized equipment configuration. As a result of process and hardware development, InP pillars with vertical and straight sidewalls were fabricated. The sidewall profile was highly straight and no distortion was seen. This sidewall profile is promising for InP-based laser diode with excellent optical properties.
Samco possesses experienced process knowledge of InP plasma etching. We will optimize and offer InP etching processes based on customers’ process demands on etching profile (shape and geometry).
Any questions on our process capabilities?
InP arrays were fabricated for surface emitting laser diode fabrication.
Etch Rate : 920 nm/min
Data courtesy of University of Delaware
InP Ridge Etching
The etched profile shows vertical sidewalls. This process is used for InP waveguide fabrication.
Etch Rate : 350 nm/min
Etch Mask : Oxide
Process capability depends on sample size and process condition.
The etched profile shows vertical sidewalls. This process is used for InP waveguide fabrication.
Etch Depth : 2.83 µm
Etch Rate : 565 nm/min
Sidewall Angle : 88°
Etch Selectivity : 15.5 (over SiN mask)
Process capability depends on sample size and process condition.
InP Lens Fabrication
Round-shape InP lens structure was fabricated using chlorine chemistry.
Etch Selectivity : 1.1 (over photoresist)
System Lineup for InP Plasma Etching
RIE Systems
– Excellent InP etch uniformity over the wafers
– Optional optical/Interferometric end-point detection
– Easy-to-use touch-panel GUI
ICP Etch Systems
– ICP plasma sources optimizing GaN etch profile control
– Optional optical/Interferometric end-point detection
– Easy-to-use touch-panel GUI
Testimonial
SAMCO’s InP etching technologies are used for R&D and production of photonic devices and RF devices at facilities including
