Apparatus for and method of etching
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorShigenori Sakamori
Life of this patent
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Abstract
A film thickness measuring mechanism is provided in an orienter chamber (A or B) or a transport buffer chamber (5) of an etching apparatus. A wafer subjected to a predetermined etching process in an etching chamber (1), for example, is transported temporarily into the orienter chamber (A or B) or the transport buffer chamber (5) in which the film thickness measuring mechanism, in turn, measures an etch depth for the wafer. If the etch depth is out of predetermined tolerance with respect to an etch depth setting, an additional etching process is performed on the wafer. Etch time for the additional etching process is calculated from the actual etch depth measured by the film thickness measuring mechanism, the etch depth setting, and an etch rate of a film to be etched.
Claims14
An etching apparatus having an etching chamber for etching a film formed on a surface of a wafer, and at least one of a buffer chamber and an orienter chamber for establishing an orientation of said wafer, said etching apparatus comprising:
- an etching device provided in said etching chamber for performing said etching;
- and
- an etch depth measuring device provided in one of said buffer chamber and said orienter chamber for measuring an etch depth resulting from said etching,
- wherein said etching device additionally performs said etching if said etch depth measured by said etch depth measuring device is less than a predetermined value.
A method of etching a film formed on a surface of a wafer to a predetermined depth less than the thickness of said film, said method comprising the steps of:
- (a) etching said film formed on a surface of a first wafer for first etch time;
- (b) measuring a first etch depth, said first etch depth being an actual etch depth resulting from said etching in said step (a);
- and
- (c) additionally performing said etching for additional etch time if said first etch depth is less than a predetermined value,
- wherein said first etch time is calculated from an etch depth setting for said etching in said step (a) and a first etch rate, said first etch rate being an actual etch rate estimate, and
- wherein said additional etch time is calculated from said etch depth setting, said first etch depth and an additional etch rate, said additional etch rate being an actual etch rate estimate for said etching in said step (c).
A method of etching a film formed on surfaces of a plurality of wafers to a predetermined depth less than the thickness of said film, said method comprising the steps of:
- (a) performing said etching on said film formed on a surface of a first wafer for first etch time;
- (b) measuring an actual etch depth resulting from said etching in said step (a);
- and
- (c) performing said etching on said film formed on a surface of a second wafer for second etch time, said step (c) being performed after said step (b),
- wherein said second etch time T2 is calculated in accordance with the equation
- T2=Dset/(Dact/T1)
- where Dset is an etch depth setting for said etching, Dact is said actual etch depth measured in said step (b), and T1 is said first etch time.
Dependencies are inferred from the claim text.