PRESSURE SENSOR AND MANUFACTURING METHOD OF THE SAME

• Main Author: HAYAKAWA YUTAKA
• Format: Patent
• Language: English; Japanese
• Published: 08.02.2016
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MEASURING; MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE; PHYSICS; SEMICONDUCTOR DEVICES; TESTING

PROBLEM TO BE SOLVED: To provide a pressure sensor capable of suppressing out-diffusion of impurities within a reference pressure chamber from re-diffusing to portions around a gauge resistance out of a semiconductor layer of a sensor chip, and a method of manufacturing the pressure sensor.SOLUTION: A pressure sensor S1 in which a gauge resistance 16 is separated into a plurality of portions across a separation portion 19 that is part of a diaphragm 18 and that separates the gauge resistance 16 in a cross-section cut in a direction perpendicular to a first surface 10a, is configured as follows. The pressure sensor S1 is configured so that trenches 19a are formed in the first surface 10a of the separation portion 19 and insulating films 19b are formed on inner wall surfaces of the respective trenches 19a. With this configuration, in the pressure sensor S1, the insulating films 19b prevent out-diffusion of impurities from the gauge resistance 16 into a reference pressure chamber 30 when a high-temperature heat treatment is carried out, and it is difficult to cause leakage current to flow between the plural separated portions of the gauge resistance 16 across the separation portion 19.SELECTED DRAWING: Figure 2 【課題】基準圧力室内に外方拡散した不純物がセンサチップの半導体層のうちゲージ抵抗の周囲の部分に再拡散し難い圧力センサおよびその製造方法を提供する。【解決手段】第１面１０ａに垂直な方向に切断された断面において、ゲージ抵抗１６が、ダイヤフラム１８の一部であってゲージ抵抗１６を分離する分離部１９を挟んで複数の部分に分離された圧力センサ１において、以下の構成とする。すなわち、圧力センサＳ１を、分離部１９における第１面１０ａにトレンチ１９ａが形成され、トレンチ１９ａの内壁面に絶縁膜１９ｂが形成された構成とする。これにより、この圧力センサＳ１では、高温熱処理をしたときに、不純物がゲージ抵抗１６から基準圧力室３０内に外方拡散しようとしても、絶縁膜１９ｂによって妨げられ、分離部１９を挟んだ複数のゲージ抵抗１６部分の間でリーク電流が流れてしまう事態が生じ難くなる。【選択図】図２