Pressure sensor for micro electro-mechanical system and production method thereof

Abstract

The invention provides a method for manufacturing micro-electro-mechanical system (MEMS) pressure sensors. The method comprises the following steps: a pressure chamber opening is formed in a semiconductor substrate; an insulator upper silicon substrate is bonded to the semiconductor substrate so as to form a pressure chamber; the insulator upper silicon substrate comprises a top silicon layer, an oxygen embedding layer and a substrate silicon layer, wherein the top silicon layer is bonded to the semiconductor substrate; the substrate silicon layer is removed till exposing the oxygen embedding layer; a silicon oxide layer is formed on the oxygen embedding layer; the silicon oxide layer and the oxygen embedding layer are etched till exposing the top silicon layer, so as to form an opening corresponding to the position of a follow-up sensitive resistor; ions are injected into the top silicon layer along the opening, so as to form a sensitive resistor; a conducting layer is formed on the silicon oxide layer; and the opening is filled with the conducting layer, so as to form an electrode communicated with the sensitive resistor. The invention also provides an MEMS pressure sensor. The method can accurately control the thickness of a sensitive film and the position of the sensitive resistor, thereby improving the sensitivity and linearity of the pressure sensor.

Description

technical field [0001] The invention relates to the field of semiconductor device manufacturing, in particular to a micro-electromechanical system pressure sensor and a manufacturing method thereof. Background technique [0002] MEMS is a tiny device that integrates microelectronic circuits and micromechanical brakes. It can use sensors to receive external information, amplify the converted signals through circuit processing, and then change them into mechanical operations by actuators to execute information commands. . It can be said that MEMS is an integrated device that acquires, processes information and performs mechanical operations. [0003] According to the above principles, the existing MEMS pressure sensor receives external gas pressure through a sensitive membrane, and then converts it into an electrical signal to measure specific pressure information. [0004] The existing technological process for making MEMS pressure sensors, such as figure 1 As shown, a sem...

AI Technical Summary

Problems solved by technology

[0009] In the prior art, potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAH) or ethylenediamine-o- Hydroquinone-water (EPW) solution etches the semiconductor substrate. Because the uniformity of the wet etching speed is difficult to control, the thickness uniformity of the sensitive film cannot be accurately controlled, which in turn affects the position of the sensitive resistor and the pressure chamber. And the thickness of the sensitive film does not meet the design requirements, which affects the sensitivity and linearity of the pressure sensor

Images