Paper PS-TuP10
Atomic Scale Etch Depth Control and Low Damage Etching of III-V Compound Materials using Cl₂ Atomic-Layer Etching

Tuesday, October 19, 2010, 6:00 pm, Room Southwest Exhibit Hall

III-V compound materials have been used for the devices such as high electron mobility transistors (HEMTs), light emitting diodes (LEDs), and quantum dot (QD) devices due to its excellent material properties including high carrier mobility, wide operating temperate range, direct energy band structure, etc. For the fabrication of these III-V compound materials devices, reactive ion etching techniques such as capacitively coupled plasma etching, inductively coupled plasma (ICP) etching, etc. are generally applied to obtain anisotropic etching properties. However, due to the energetic reactive ions involved in the reactive ion etch process, the surface of the etched III-V compound materials tends to be damaged physically and chemically by structural disruption, intermixing, stoichiometric modification, surface roughening, etc. In addition, it is difficult to control the etch depth precisely through the reactive ion etching due to the fluctuation of the etch process. To overcome these problems, various atomic layer etching techniques (ALETs) have been investigated especially as the application to the nano-device processing which requires atomic-scale precision in the etching in addition to the nearly no-damage to the surface during the etching .

The etch characteristics of III-V compound materials by ALET were investigated using a Cl₂-based ALET. The effect of ALET on surface modification and etch-depth control was also examined. Self-limited etching of III-V compound materials could be obtained using Cl₂ ALET. In addition, the significant improvement in the electrical properties of the III-V device could be obtained by etching the damage sensitive layer using ALET.