Semiconductor sensor chip and method for producing the chip, and semiconductor sensor and package for assembling the sensor

A method of making an angular acceleration sensor chip comprising:

• (a) a step for preparing a SOI wafer comprising a silicon substrate, a SiO2 layer and a silicon thin film;
• (b) a step for ion implanting a dopant at a position corresponding to a semiconductor strain gauge of said silicon thin film to form a diffusion resistor, forming a magnetic thin film at a position corresponding to a weight part, forming a detection coil surrounding said magnetic thin film, and forming devices necessary for circuit construction on said silicon thin film;
• (c) a step for providing a protective film on the entire surface of said wafer, opening a plurality of through holes penetrating said silicon thin film by patterning and etching, and forming a beam part connecting to said weight part and a support frame part remained on the periphery;
• (d) a step for removing said SiO2 layer under said weight part and said beam part by wet etching for forming said plurality of through holes while retaining said protective film;
• (e) a step for removing said protective film;
• (f) a step for coating a resist over the entire surface of said wafer;
• (g) a step for forming a slit by dicing for dividing said chip while retaining a small thickness of said wafer;
• (h) a step for removing by ashing said resist on said wafer by an O2 plasma;
• and
• (i) a step for dividing said chip by concentrating a stress on said slit.

A method of making an acceleration sensor chip comprising:

• a step for providing SOI wafer comprising a first layer of support substrate, an insulating second layer and a silicon thin film third layer;
• a step for forming a plurality of cutouts of a same width on said third layer to form a sensor structure having a beam part and a weight part for displacing said beam part which are separated from each other;
• a step for forming a circuit part connected electrically to said sensor structure in the periphery of said third layer;
• a step for removing said second layer located beneath said sensor structure to make said beam part and said weight part provided on said sensor structure displaceable.

A method of making an acceleration sensor chip for constructing a sensor structure on a third layer provided on a first layer of support substrate through an insulating second layer, comprising:

• a first step for forming a plurality of cutouts of a same width on said third layer to form a detection surface of said sensor structure having a beam part and a weight part for displacing said beam part which are separated from each other;
• a second step for filling said plurality of cutouts of said same width of said sensor structure with a sealing agent to flatten the surface of said third layer including said sensor structure;
• a third step for forming a circuit part connected electrically to said sensor structure in the periphery of said surface-flattened third layer;
• and
• a fourth step for removing said sealing agent filled in said plurality of cutouts of said same width and removing said second layer located beneath a detection surface of said sensor structure to make said beam part and said weight part provided on said detection surface of said sensor structure displaceable.