A kind of stripping means of semiconductor laser chip metalTechnical field
The present invention relates to integrated circuit and microelectromechanical systems manufacture field more particularly to a kind of semiconductor laser coresThe stripping means of piece metal.
Background technology
In microelectromechanical systems (MEMS) and integrated circuit processing technique, some materials metal such as gold, titanium, nickel,It is difficult to do mask with photoresist, is corroded by chemical reagent and Tiny figure；Some multiple layer metals are replaced with different corrosive liquidsSerious lateral undercutting can occur when use；Some metal erosion liquid can have corrosiveness to subsurface material.
Metal lift-off material is to coat a layer photoresist in substrate surface, the region for not needing metal by cross front baking,Exposure, development form mask pattern；Substrate surface sputter or be deposited method plate metal film, finally impregnate stripper orPhotoresist is dissolved removing by acetone soln, and the metal of photoresist surface thereon also falls off with it together, required to leaveMetallic pattern.The metal film of stripping means being critical that on photoresist is disconnected with the metal film in mask areas of disconnection, in this wayLiquid infiltration is easily peeled off to enter to dissolve photoresist.Some toxicity of the solution that common method for stripping metal uses are big, technique is numerousTrivial, expensive raw material price；For example, by using layered mask stripping method：In substrate base layer spin coating LOR glue, after overbaking is handled；AgainThe spin coating positive photoresist on LOR glue, prepares desired figure by way of exposing, developing.In actual mechanical process,LOR glue is more sticky, during spin coating LOR glue, easily forms gap between substrate and LOR glue, in developing process, can figure collapse,Make aliasing；Secondly LOR can form buffings in substrate edge, influence lithographic accuracy after overbaking is handled.
Invention content
In view of this, being to realize the purpose of the present invention is to provide a kind of stripping means of semiconductor laser chip metalAbove-mentioned purpose, the present invention adopt the following technical scheme that：A kind of stripping means of semiconductor laser chip metal, step packetIt includes：
Step S1：With photoresist by substrate spin coating；
Step S2：Substrate after spin coating is subjected to front baking processing, hot plate temperature is 90 DEG C -105 DEG C, -70 seconds 50 seconds time；
Step S3：Rotine exposure is carried out with reticle；
Step S4：Substrate is positioned on hot plate and carries out reversion baking processing, hot plate temperature is 110 DEG C -125 DEG C, the 60 seconds time -100 seconds；
Step S5：Place the substrates in cooling in air, time 3-5 minute；
Step S6：Substrate is subjected to pan-exposure processing, time 60-90 second；
Step S7：Substrate is put into developing liquid developing, makes photoresist picture that eaves shape be presented and falls from power；
Step S8：Substrate is put on 110 DEG C of -125 DEG C of hot plates and carries out post bake, -100 seconds 60 seconds time；
Step S9：Substrate treatment is cleaned；
Step S10：Substrate is put into sputtering unit sputtering or evaporation deposited metal film；
Step S11：Substrate is put into stripper, photoresist and excess metal are removed；
Further, the photoresist of the step S1 is single layer AZ5200E sequence of photolithography glue.
Further, the film thickness of the substrate spin coating of the step S1 is 2-3um.
Further, it is acetone or photoresist lift off liquid, 5-10 points of soaking time that the stripper of the step S11, which uses,Clock.
Further, the metal of different-thickness can be removed by the film thickness of spin coating described in rate-determining steps S1.
The present invention has the advantages that compared with prior art：The present invention uses single layer AZ5200E sequence of photolithography glue（Such as AZ5214E）Tackifier, gluing, front baking, mask exposure, reversion baking, pan-exposure, development are coated, realizes image inversion；It is compared compared to conventional lift-off process, present invention process step is simple, and high yield rate is at low cost；The room that the metal of precipitation is formedEaves shape photoresist is disconnected in masked areas, is facilitated the infiltration of stripper, is conducive to remove.
Description of the drawings
Fig. 1 is that the obtained eaves shape of present invention development is fallen from power photoresist side wall
Fig. 2 is the sectional view that the present invention completes metal-stripping.
Specific implementation mode
The present invention will be further described with reference to the accompanying drawings and embodiments.
Fig. 1 is please referred to, the present invention provides a kind of stripping means of semiconductor laser chip metal, and step includes：
Step S1：With photoresist by substrate spin coating；
Step S2：Substrate after spin coating is subjected to front baking processing, hot plate temperature is 90 DEG C -105 DEG C, -70 seconds 50 seconds time；
Step S3：Rotine exposure is carried out with reticle；
Step S4：Substrate is positioned on hot plate and carries out reversion baking processing, hot plate temperature is 110 DEG C -125 DEG C, the 60 seconds time -100 seconds；
Step S5：Place the substrates in cooling in air, time 3-5 minute；
Step S6：Substrate is subjected to pan-exposure processing, time 60-90 second；
Step S7：Substrate is put into developing liquid developing, makes photoresist picture that eaves shape be presented and falls from power；
Step S8：Substrate is put on 110 DEG C of -125 DEG C of hot plates and carries out post bake, -100 seconds 60 seconds time；
Step S9：Substrate treatment is cleaned；
Step S10：Substrate is put into sputtering unit sputtering or evaporation deposited metal film；
Step S11：Substrate is put into stripper, photoresist and excess metal are removed；
Further, the photoresist of the step S1 is single layer AZ5200E sequence of photolithography glue.
Further, the film thickness of the substrate spin coating of the step S1 is 2-3um.
Further, it is acetone or photoresist lift off liquid, 5-10 points of soaking time that the stripper of the step S12, which uses,Clock.
Further, the metal of different-thickness can be removed by the film thickness of spin coating described in rate-determining steps S1.
The foregoing is merely presently preferred embodiments of the present invention, all equivalent changes done according to scope of the present invention patent withModification should all belong to the covering scope of the present invention.