Structure Feature Analysis And The Optimization Of Process Parameters About An Etching Machine In The Chamber

The core of semiconductor process technology is Etching，with the increase of thewafer radius and the decrease of its feature sizes constantly, higher and higherrequirements of etching process is put forward． Based on the new18-inch wet etchingchamber etching, coupling relationship of flow field, thermal field and chemicalreaction is presented in the cylindrical chamber containing dry etching； Interiorfeatures of space distribution of velocity, pressure, temperature is analyzed in theetching chamber with different structure and process parameters，then：By mastering etching machine structure, working principle and its involving fluidmechanics equation and boundary condition equations and analyzing technologicalprocess of hydrofluoric acid etching sio2process, it put forward the etching rate andetching inhomogeneity (etching process indicators) estimation formula, which isdecided by the dissipation coefficient, material conversion coefficient, mass flux, andlattice structure, of coupled thermal field, flow field, field, and research the influence ofsingle factor parameters on the technical index． It gets the influence of the etchingdistribution characteristics by them．For the mathematical functions between parameters and etching process, theadaptive genetic algorithm based on the response surface method (RSM) is put forwardby analyzing of the RSM, central composite design, genetic algorithm． The responserelationship between the Vmass, r3, p1, p2, Gap and etching process research is studiedby the way． It gets the optimal structure parameters and process parameters of etchingprocess, which is adopted in a project．It is found on the above analysis, that: flow rate is extremely low in the center ofthe baffle, thus it puts forward curved surface modification； Closed damping platechamber structure is put forward as the baffle threatening the etching rate and etchinginhomogeneity effect was not significant； A double export structure design aboutetcher is put forward as it seriously causes changes of the exit velocity, temperature andaxial velocity on the edge； Curved surface structure about showerhead is put forward,based on porous medium osmotic pressure drop seriously, then the rationality of the newstructure is assessed based on the spatial distribution of etching rate to find the optimalchamber structure．...