NOVELTY - The method involves plasma cleaning sacrificial material out of an aperture from a planar surface. A silicon substrate (32) is provided. The substrate is sealed to the planar surface of a wafer substrate to define a chamber (58) containing fluid i.e. air, at reference pressure, where a corrugated non-planar flexible membrane (50) deflects due to pressure differentials between the reference pressure and external fluid pressure to be sensed during use such that a circuitry converts the deflection of the flexible membrane into an output signal indicative of the external fluid pressure.    USE - Method for lithographically fabricating a micro-electro mechanical (MEMS) tire pressure sensor i.e. capacitive pressure sensor, for sensing fluid pressure i.e. air pressure, in an industry for engine pressure monitoring applications in cars, aircraft, ships and fuel cells, dish-washing machine applications, domestic and industrial iron applications, high speed wind tunnel applications, explosion monitoring applications and boiler applications. Can also be used for a piezo-resistive pressure sensor, resonant pressure sensor and a force compensation pressure sensor.    ADVANTAGE - The method enables providing the sensor that is robust and highly versatile. The method allows the sensor to reduce effects of acceleration due to decreased mass. The method enables providing high volumes and high yields that dramatically reduce unit cost of the sensors. The method enables minimizing thickness of the membrane to allow usage of high yield strength membrane material so as to reduce area of the membrane, thus reducing power consumption and size of the sensor.    DETAILED DESCRIPTION - The flexible membrane is deposited by sequentially depositing layers e.g. complementary metal-oxide-semiconductor (CMOS) layers (34), conductive layers (36) and passivation layers (37), of different electrically conductive material e.g. metal ceramic, to form a laminate.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of a sensor.    Silicon substrate (32)    CMOS layers (34)    Conductive layers (36)    Passivation layers (37)    Corrugated non-planar flexible membrane (50)    Chamber (58)