Precise Formation of Dovetail Structures for InP-Based Devices

Abstract

Anisotropic etching of InP along specific crystallographic directions leads to negative sidewall angles along dovetail direction. This is an important process for self-alignment of electrical contacts where sub-micron alignment is needed. However, existing etching methods are only suitable for shallow etching, and for stress-free layers. Here we demonstrate a new etching method that is capable of producing dovetail patterns with 10 times larger etch depth, and where interface stress exists. We believe this new etching method is useful for many electronic and optoelectronic devices that require precise negative angle sidewalls in their fabrication scheme.

Efficient luminescence extraction strategies and anti-reflective coatings to enhance optical refrigeration of semiconductors

“…Such techniques can be used for wet etching of active III-V and II-VI photonic materials as well which are the main candidates for semiconductor laser cooling. As an example, for InP substrates, instead of 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 KOH, HCl-based solutions should be used as highly-anisotropic etchant for InP based compositions [99] and a proper mask should be chosen to resist the etchant without introducing surface damage or unwanted background absorption of the pump and PL .…”