Fabrication of Smooth GaN-Based Laser Facets

A method is presented for fabricating fully wet-etched InGaN/GaN laser cavities using hotoenhanced electrochemical wet etching followed by crystallographic wet etching. Crystallographic wet chemical etching of n- and p-type GaN grown on c-plane sapphire is achieved using H3PO4 and various hydroxides, with etch rates as high as 3.2.μm/min. The crystallographic GaN etch planes are {0001}, {100}, {10}, {10}, and {103}. The vertical {100} planes appear perfectly smooth when viewed with a field-effect scanning electron microscope (FESEM), indicating a surface roughness less than 5 nm, suitable for laser facets. The etch rate and crystallographic nature for the various etching solutions are independent of conductivity, as shown by seamless etching of a p-GaN/undoped, high-resistivity GaN homojunction.

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Fabrication of Smooth GaN-Based Laser Facets

MRS Proceedings ◽

10.1557/proc-537-g7.5 ◽

1998 ◽

Vol 537 ◽

Author(s):

D. A. Stocker ◽

E. F. Schubert ◽

K. S. Boutros ◽

J. M. Redwing

Keyword(s):

Surface Roughness ◽

Chemical Etching ◽

Field Effect ◽

Etch Rate ◽

Wet Etching ◽

High Resistivity ◽

Wet Chemical ◽

Wet Chemical Etching ◽

P Type ◽

Scanning Electron

AbstractA method is presented for fabricating fully wet-etched InGaN/GaN laser cavities using photoenhanced electrochemical wet etching followed by crystallographic wet etching. Crystallographic wet chemical etching of n- and p-type GaN grown on c-plane sapphire is achieved using H3PO4 and various hydroxides, with etch rates as high as 3.2 μm/min. The crystallographic GaN etch planes are {0001}, {1010}, {1011}, {1012}, and {1013}. The vertical {1010} planes appear perfectly smooth when viewed with a field-effect scanning electron microscope (FESEM), indicating a surface roughness less than 5 nm, suitable for laser facets. The etch rate and crystallographic nature for the various etching solutions are independent of conductivity, as shown by seamless etching of a p-GaN/undoped, high-resistivity GaN homojunction.

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Wet Chemical Etching of Zn-containing oxides and HfO2 for the fabrication of Transparent TFTs

MRS Proceedings ◽

10.1557/proc-1201-h10-25 ◽

2009 ◽

Vol 1201 ◽

Author(s):

Jae-Kwan Kim ◽

Jun Young Kim ◽

Seung-Cheol Han ◽

Joon Seop Kwak ◽

Ji-Myon Lee

Keyword(s):

Sulfuric Acid ◽

Surface Morphology ◽

Chemical Etching ◽

Etch Rate ◽

Room Temperature ◽

Wet Chemical ◽

Wet Chemical Etching

AbstractThe etch rate and surface morphology of Zn-containing oxide and HfO2 films after wet chemical etching were investigated. ZnO could be easily etched using each acid tested in this study, specifically sulfuric, formic, oxalic, and HF acids. The etch rate of IGZO was strongly dependent on the etchant used, and the highest measured etch rate (500 nm/min) was achieved using buffered oxide etchant at room temperature. The etch rate of IGZO was drastically increased when sulfuric acid at concentration greater than 1.5 molar was used. Furthermore, etching of HfO2 films by BF acid proceeded through lateral widening and merging of the initial irregular pits.

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