CN102677161B - Removing method for residual liquid on back of tellurium-cadmium-mercury liquid phase epitaxial thin film - Google Patents

Abstract

The invention discloses a removing method for residual liquid on the back of a tellurium-cadmium-mercury liquid phase epitaxial thin film. The removing method is characterized by leading an originally unusable tellurium-cadmium-mercury material with the residual liquid on the back to be normally used by using a chemical corrosion and mechanical polishing method under the condition that the quality of the material is not affected. A device and the method have the advantages that in the whole process, as the surface of the cleaned tellurium-cadmium-mercury epitaxial thin film is always protected by a photoresist, the tellurium-cadmium-mercury epitaxial thin film can not be polluted and oxidized and also can not be scratched due to the contact with hard objects, and the cleanness and the perfect surface of the epitaxial thin film are ensured. The technology has the advantages that the originally unusable epitaxial thin film can be used after being treated, and simultaneously the quality of the epitaxial thin film is also ensured not to be affected, thereby greatly increasing the rate of finished products of tellurium-cadmium-mercury liquid phase epitaxial thin film preparation.

Description

The removal method of mercury cadmium telluride rheotaxial film back side raffinate

Technical field

The present invention relates to semiconductor wafer fabrication process method, be specifically related to the removal art treatment of the vertical rheotaxial growth of a kind of Te-Cd-Hg back side raffinate.

Technical background

For the infrared Hg-Cd-Te material of preparing for rheotaxial growth mode, conventionally at the tellurium cadmium mercury epitaxial layer of tellurium zinc cadmium Grown one deck 10-20 micron.But in reality growth, a certain amount of raffinate of generation that vertical impregnated growth or the growth of horizontal push boat type all can be more or less, raffinate problem is also one of factor affecting for a long time Hg-Cd-Te material usable floor area and quality.Be difficult to remove close to the common polishing mode of the noncrystal use of silicon materials because growth raffinate is hardness, and raffinate is light tight can not carry out the measuring and calculating of spectrum, more can not on the material that has raffinate, carries out the making of device.Therefore, raffinate problem has had a strong impact on the yield rate of rheotaxy Hg-Cd-Te material for a long time.

As a rule level pushes away raffinate that boat forms taking print surface surrounding raffinate as main, and this type of raffinate can solve by the way of excision surrounding.But the extension that the growth pattern of vertical impregnated extension forms is mainly main by back side raffinate, and usually form the complete sticky situation in the just whole back side.This type of raffinate is wanted to remove and will be ensured that the tellurium cadmium mercury epitaxial layer on epitaxial film surface is not damaged, and ensures that again raffinate layer removes completely, therefore in actually operating, has suitable difficulty.

Summary of the invention

The object of this invention is to provide the Transformatin method of a kind of mercury cadmium telluride rheotaxial film back side raffinate, this method solved the back side in rheotaxy film preparation the problem that reduces of yield rate that sticky residuals causes.

This art treatment step is as follows:

1) in class 100 clean room, extension film surface is carried out to the even glue of photoresist material with thin glue and protect and cut, epitaxial film sample surfaces surrounding raffinate is excised;

2) choose a clean glass disk and be placed on temp. controllable electric furnace, temperature is adjusted to 80 degrees Celsius.After glass disc heats up, be coated with 5 centimetres of lastblocks in its centre region and be multiplied by the wax of 5 centimetres, subsequently epitaxial film sample is had raffinate towards upper, being placed horizontally at glass disk waxes in the region of having melted, after paster completes, take off glass disc and be placed on easy heat conduction and heat radiation place, after wax condenses completely with blade along epitaxial film edge the careful wax of surrounding must being scraped off;

3) first rinse glass disc surface with trieline, to remove residual wax, oil and pickup, rinse glass disc surface with a large amount of alcohol again, cleaned glass disc paster is faced up be soaked in newly to join in chloroazotic acid subsequently and corrode after 1 minute to 10 minutes, after 30 seconds, dry with a large amount of deionized water rinsings;

4) there is the back side of raffinate to carry out successively the mechanical rough polishing of 15-20 minute and the chemistry of 10 minutes, mechanical finishing polish with polishing machine to extension film sample, thoroughly remove the raffinate at the epitaxial film sample back side;

5) by processed raffinate complete epitaxial film sample together with glass disc place with temp. controllable electric furnace on, temperature is adjusted to 80 degrees Celsius, until wax melt after epitaxial film is taken off;

6) dewax carried out in extension film sample surface and go photoresist material to clean;

7), in class 100 clean room, the even glue protection of photoresist material is carried out to thin glue in extension film sample surface.

Brief description of the drawings

Fig. 1: the method flow diagram of mercury cadmium telluride rheotaxial film back side viscosity raffinate.

Fig. 2 (a): the epitaxial film back side before raffinate is removed; (b): the epitaxial film back side before raffinate is removed.

Embodiment

Below in conjunction with accompanying drawing, specific embodiment of the invention flow process is shown in to Fig. 1 is described in further details:

1. even glue mainly plays the effect on protection epitaxial film surface.In this treatment process, take the technique with twice, the even glue of thin glue.Rotating speed is first 3 seconds 200, rear 30 seconds 2000 revs/min.

2. the effect that makes epitaxial film back side raffinate looseization of part and part take out raffinate is mainly played in chloroazotic acid corrosion.Because traditional tellurium zinc cadmium polishing technology pressurization great Yi throws the epitaxial film of back side raffinate broken, pressurize and littlely back side raffinate cannot be removed.Therefore, chloroazotic acid corrosion is the most crucial technique of the present invention.

3. getting sheet link and be the most easily damaged to the tellurium cadmium mercury epitaxial layer on epitaxial film surface.In this technique, glass disc must be heated completely, treat that wax melts desirable of rear completely.On getting in sheet process as epitaxial film conduct route, without wax, must on glass disc, coat enough wax in order to avoid produce wire drawing.The epitaxial film of not removing raffinate is shown in that Fig. 2 (a) and the epitaxial film back side of having removed raffinate sees that Fig. 2 (b) comparison diagram is as follows.

4. cleaning is also a step of taking out photoresist material and wax, and this step is mainly used trieline, methyl alcohol and Virahol.Concrete steps are as follows: (a) epitaxial film is faced up and is positioned in tetrafluoro utensil.(b) three times dewaxs of trieline heating bath, deoil, go pickup.(c) in methyl alcohol, clean three times.(d) in acetone, clean three times, to remove photoresist material.(e) in methyl alcohol, clean three times.(f) Virahol cleans three times, is heated to for the third time after boiling point, epitaxial film be taken out, and puts into and preserves vessel.Finally carry out Coating glue protect.Finished product sheet.

Claims (1)

1. a removal method for mercury cadmium telluride rheotaxial film back side raffinate, is characterized in that comprising the following steps:

1) in class 100 clean room, extension film surface is carried out to the even glue of photoresist material with thin glue and protect and cut, epitaxial film sample surfaces surrounding raffinate is excised;

2) choosing a clean glass disk is placed on temp. controllable electric furnace, temperature is adjusted to 80 degrees Celsius, after glass disc heats up, be coated with 5 centimetres of lastblocks in its centre region and be multiplied by the wax of 5 centimetres, subsequently epitaxial film sample is had raffinate towards upper, being placed horizontally at glass disk waxes in the region of having melted, after paster completes, take off glass disc and be placed on easy heat conduction and heat radiation place, after wax condenses completely with blade along epitaxial film edge the careful wax of surrounding must being scraped off;

3) first rinse glass disc surface with trieline, to remove residual wax, oil and pickup, rinse glass disc surface with a large amount of alcohol again, cleaned glass disc paster is faced up be soaked in newly to join in chloroazotic acid subsequently and corrode after 1 minute to 10 minutes, after 30 seconds, dry with a large amount of deionized water rinsings;

4) there is the back side of raffinate to carry out successively the mechanical rough polishing of 15-20 minute and the chemistry of 10 minutes, mechanical finishing polish with polishing machine to extension film sample, thoroughly remove the raffinate at the epitaxial film sample back side;

5) by processed raffinate complete epitaxial film sample together with glass disc place with temp. controllable electric furnace on, temperature is adjusted to 80 degrees Celsius, until wax melt after epitaxial film is taken off;

6) dewax carried out in extension film sample surface and go photoresist material to clean;

7), in class 100 clean room, the even glue protection of photoresist material is carried out to thin glue in extension film sample surface.