Moisture-free sog process
AssigneeMitel Corporation
InventorLuc Ouellet
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Abstract
In a method of planarizing a semiconductor wafer having aluminum interconnect tracks formed thereon, a method is disclosed for applying inorganic spin-on glass which comprises applying the spin-on glass to the wafer in a coating and spinning chamber in a moisture-free environment, transferring the wafer in a moisture-free environment to a curing station, curing the spin-on glass at a temperature in the range of about 80.degree. to 250.degree. C. in the moisture-free environment at the curing station, and returning the wafers to the coating and spinning chamber. The above steps are repeated until a sufficient film thickness has been achieved without in the interim exposing the wafer to moisture conditions such that reverse hydrolysis si minimized during the planarization process. In this way crack-free inorganic SOG films can be produced.
Claims7
A method of planarizing a semiconductor wafer having interconnect tracks of non-refractory material formed thereon, comprising the steps of:
- i) applying a layer of inorganic phosphorus-based spin-on glass to the wafer in a coating and spinning chamber in the absence of moisture;
- ii) transferring the wafer in the absence of moisture to a curing station;
- (iii) curing the spin-on glass at a temperature in the range of at least about 80.degree. C. and not more than 450.degree. C. in the absence of moisture at said curing station to form an SiO.sub.2 lattice connected to phosphorus atoms;
- (iv) returning the wafer to the coating and spinning chamber and repeating steps (i) to (iii) until a sufficient film thickness has been achieved without in the interim exposing the wafer to moisture so as to minimize reverse hydrolysis during a planarization process and thereby prevent irreversible reactions that form phosphorus acids and thus lead to disconnection of the phosphorus atoms from the SiO.sub.2 lattice.
Dependencies are inferred from the claim text.