A Sensor for Breath Alcohol Measurement Using Porous Silicon and Fabrication Method Thereof

摘要

PURPOSE: An alcohol sensor and a producing method thereof are provided to produce the alcohol sensor by using porous silicon as a detect material for reduce size of the alcohol sensor while reducing producing cost. CONSTITUTION: A second conductive typed epitaxal layer(30) is formed on a high density silicon substrate(10) of a first conductive type. Herein, a P+ typed substrate having specific resistance of 0.01 ohm cm. Therefore, an ohmic bond is formed without depositing a separate metallic electrode in an anode reaction to form a porous silicon. A porous silicon layer(20) is formed on the high density silicon substrate through ion injection of dopant and selective anode reaction. Moreover, an exposed area of the silicon substrate separated from the porous silicon layer is formed on the epitaxal layer. Then, an electrode unit is formed on the porous silicon layer and the exposed area for detecting alcohol density. Herein, two electrodes(50) are formed at specific portions on the porous silicon layer and the exposed area while forming a protect layer(40) at the other portions of the porous silicon layer and the exposed area to protect elements. Herein, a space between the electrodes is limited by the porous silicon layer. Moreover, the electrodes are formed on an upper end of a wafer to reduce size of an alcohol sensor.