Pre-photolithographic GaAs surface treatment for improved photoresist adhesion during wet chemical etching and improved wet etch profiles.

Conference · Sat May 01 04:00:00 EDT 2010

OSTI ID:1014645

Martinez, Marino John; Clevenger, Jascinda; Austin, IV, Franklin H ^[1]; Sullivan, Charles Thomas; Patrizi, Gary A; Romero, Katherine ^[2]; Timon, Robert P; Vigil, Pablita S ^[2]; Grine, Alejandro J

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1. , LMATA, Albuquerque, NM
2. LMATA, Albuquerque, NM

Results of several experiments aimed at remedying photoresist adhesion failure during spray wet chemical etching of InGaP/GaAs NPN HBTs are reported. Several factors were identified that could influence adhesion and a Design of Experiment (DOE) approach was used to study the effects and interactions of selected factors. The most significant adhesion improvement identified is the incorporation of a native oxide etch immediately prior to the photoresist coat. In addition to improving adhesion, this pre-coat treatment also alters the wet etch profile of (100) GaAs so that the reaction limited etch is more isotropic compared to wafers without surface treatment; the profiles have a positive taper in both the [011] and [011] directions, but the taper angles are not identical. The altered profiles have allowed us to predictably yield fully probe-able HBTs with 5 x 5 {micro}m emitters using 5200 {angstrom} evaporated metal without planarization.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 1014645
• Report Number(s): SAND2010-3205C
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADHESION
DESIGN
ETCHING
MANUFACTURING
OXIDES
SURFACE TREATMENTS