Semiconductor-oxide etchant
AssigneeMotorola, Inc.
InventorThomas J. Kingzett
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Abstract
An etchant for semiconductors having a high preferential etch rate for doped silica particularly phosphorous doped silica, consisting of a 20:20:1 mixture, by volume, of 37% hydrochloric acid, deionized water, and 49% hydrofluoric acid. The etchant is particularly useful in a semiconductor process wherein an emitter opening is washed out following the diffusion thereof.
Claims2
In a process wherein an emitter is formed in a silicon semiconductor through a diffusion window and an oxide formed thereover whereafter the emitter opening is cleaned out by immersing the silicon semiconductor in an etch solution the improvement comprising an etch consisting essentially of hydrochloric acid;
- hydrofluoric acid and water having a PH of less than 1.
Dependencies are inferred from the claim text.