SUB-MICRON GaAs LINES
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Sub-micron GaAs lines can be produced in epitaxial GaAs/AlGaAs material using conventional optical lithography techniques and reactive ion etching. Epitaxial layers of GaAs, AlGaAs, and GaAs on a GaAs substrate are shown in Fig. 1. A 2000 ˜ blanket of molybdenum or other selected transition element is deposited on top of the epitaxial layers. The molybdenum and epitaxial layers are patterned with photoresist, e.g., AZ1450J, and exposed using a light field mask. The layers then look as shown in Fig. 2. The width of the stencil lines can easily be achieved with conventional mask aligners and lithographic practices. With the structure of Fig. 2, the following steps are employed. Step 1 The molybdenum, or other transition metal, is etched with a CF4 and O2 mixture. The CF4 + O2 mixture will not etch the GaAs layer underneath.