The improvement of abrade surface condition mixes silicon chip the improvement of abrade fluid

A Kind Ofpolishing Slurry Is Introduced To Change The Fierce Mechanical Action Into The Tenderchemical-mechanical Action, and Some Positive Effect Can Also Be Made By It.

The Wafer Surface Condition Is Improved To Some Extent, and The Production Efficiency Is Increased.

Key Words:sIlicon Wafer; Polishing; Polishing Slurry; Stress1 foreword is in microelectronics craft, from semiconductor monocrystalline silicon pull make, the treatment, preparation to parts of an apparatus, can produce many stress; Pull marvellously from silicon make, section, grind segment arrives the polish later, accompanying many machining process and generation of many quantity of heat, produce many mechanical stress and thermal stress in silicon chip thereby 5. Grind segment has important place in the preparation process of silicon chip, it is the first time machining of surface of the silicon chip after section, next treatment that are silicon chip laid a foundation. Mix greatly as a result of the exterior tension of brittleness material in front of working procedure stress accumulate, plus violent muller instrument action, make silicon chip surface produces crackle extremely easily, serious still can bring about collapse edge, fragment, cause abominable effect to follow-up craft. Because nowadays home makes most conductor company be in this working procedure,just use simple tap water cooling, clean, lack advanced instructor, the problem that appears accordingly is more serious 6. Condition of silicon chip surface affects limits of the line wide capacity of parts of an apparatus, craft, crop and productivity directly. Of diagnostic dimension narrow the demand of quality of pair of silicon chip surface rises ceaselessly continuously 7. The problem in how solving this working procedure so has very great real sense. 2 principles are analysed and experiment 2.

The application of 1 abrade fluid is abrade of fluid introduce make solve afore-mentioned problems to become a possibility. Reduce stress method traditionally to use the lubricity that increases cutting, abrade size more, rise to come loose serously heat energy force, machine a large number of quantity of heat of generation with diffusing quickly, reduce thermal stress 8. My school introduces the certain mechanism of CMP technology in silicon chip cutting and grinding craft, according to the chemistry of silicon, use alkalescent size, join a variety of activator, improve serous physico-chemical character, increase the chemistry in processing a project, improved treatment technology greatly, alleviated violent mechanical action. Abrade fluid is comprised by a variety of composition, basically include: Organic activator of alkaline, surface and mixture of a huge legendary turtle. Use organic alkaline it is to prevent to introduce the deadly harm that the parts of an apparatus after ion of foreign matter metal gives causes. The principle is as follows ↑ of ＋ 2H2 of SiO3- of → of H2O of ＋ of Si + 2OH- is in treatment process, silicon chip can produce chemical reaction with abrade fluid, raised abrade rate and alleviated pure, violent mechanical action. This experiment uses the damage of the stress volume that distinct size measures and silicon chip for the analysis namely, compare which kind of abrade fluid effects to had been compared. 2.

Action of 2 surfaces activator and principle surface activator make the surface has active quality namely 9. Have the interface between two kinds of material to go up to gather easily, can change the interfacial character between these two kinds of material significantly, reduce solvent surface tension and corporeal interface pulling force significantly especially, have particular structure, close water lipophilic the material of character and special and adsorptive function 10. The basis kisses the different structure of water radical, can divide exterior activator for activator of surface of ion of ion surface activator, blame and special appearance activator 11. Individual activator element always keeps turning in aqueous solution, when the abhor of two activator element water radical encounters when, always attract in an attempt to to reduce place to suffer repulsion each other. Accordingly, outside dividing extremely rare solution, activator element is most in aqueous solution be with half glue bundle or bunchy condition puts glue in 12. If aqueous solution of activator of silicon chip park in, activator element is met by adsorption of silicon chip surface, of polarity kiss water radical and silicon chip to be able to form much dot adsorption. Activator element is in the adsorption of silicon chip surface sides with silicon chip in order to kiss water radical, in aqueous solution as activator element pH indicator increases, structure of structure of only member layer, double element layer can be formed in silicon chip surface even half glue bundle structural adsorption 13 14 15 16. When foreign matter grain the form with physisorption is adsorptive at silicon chip surface, join exterior activator to the middle of solution, wetting action of meeting have the aid of is in activator element quickly the exterior spread out of silicon chip and grain leaves, form a compact covering layer. Activator element kisses water radical to be able to form much dot adsorption with silicon chip surface, grain is when silicon chip face is mobile, permeate pressure those who make the free activator element in solution reachs adsorptive already activator member is close the not adsorptive free part on water radical, actively is extended between the osculatory aperture to silicon chip and grain, go up with silicon chip and grain at any time photograph of occurrence odd and free key is attracted, union, the key force that urges the action between silicon chip and grain is smaller and smaller, the absorption affinity of grain and silicon chip is ceaseless and abate, final will whole grain departs from silicon chip surface. Activator element forms compact particle covering layer in silicon chip and grain surface, prevent grain and silicon chip to form adsorption 2 times, finished grain so far the desorption 17 18 19 20 from silicon chip surface. 2.

Principle of mixture of 3 a huge legendary turtle should introduce many metallic ion inevitably in abrade treatment process, for example the surface that the iron ion on millstones may is in to process data by adsorption in abrade process, in before a few working procedure (for example: Rounded, cut, guide horn) still can take the metallic ion such as copper, magnesian, calcium. In the center of the forbidden band that metallic ion energy level is in silicon crystal around, say for impurity of deep energy level, having the compound center effect of electron and cavity, make crystal medium little child life drops greatly, leakage current increases. Because of this chela mixture use become indispensable. The main effect of mixture of a huge legendary turtle is purify metal ion, because the bases in the organic structure of activator of this kind of surface is a huge legendary turtle,close link, its two end have N-O common the electron is right, it and metallic ion action, pull its Xiang Ao to close link, go in metallic ion wrap up, namely a huge legendary turtle combines function. 2.

4 experiments process and analysis 2.

4.

1 experiment condition and equipment condition: Standard atmosphere, 24 ℃ equipment: Appearance of JZHY-180 interface tension, Mettler Toledo 320 PH plan, φ 1.

5 capillary viscosity plan, the electron says, rice of small accept of stopwatch, Zhuo Lun diameter of microscope of 200 nuclear power, metallographic microscope, bead 104.

The SiC corundum of M of 3 μ . 2.

4.

Of 2 abrade fluid because abrade fluid is reducing the surface,match produce the expected result having a competition tiny flaw, check stress is accumulated wait for a respect to having main effect, what do above all so is abrade fluid deserve to compare an experiment. My school is abrade the main problem that fluid exists is abrasive suspension, dispersive in abrade fluid sex is bad, the use that causes abrade fluid is disadvantageous. Because how this increases abrade fluid suspension and stability well,be the main problem that should solve. Main consideration adds appropriate exterior activator reasonable adjust all sorts of composition deserve to solve above problem than coming. The experiment employs dispersive agent solution 1 and 2 undertake comparative, see a table 1. Solid cent powder and go ionic water with 1:0.

The scale of 7 is deliquescent composition powder solution 1, solid cent powder and go ionic water with 1:lscale is deliquescent composition powder solution 2. Express 1 solution 1 with solution the comparison of 2 ／ of tension of PH value surface (solution of dispersive agent of S of ／ of viscosity of MN · N-1) 13.

4057533.

Solution of 59 minutes of powder 23.

4559247.

19nextpage is making up a process in, dispersive agent solution the effect of 1 is not very good, viscosity is too big, after dissolve there is partial white solid body in solution, because the scale of dispersive agent in solution is exorbitant,the consideration basically is cause solution saturation and the crystal of separate out, because this is in the experiment later,basically use dispersive agent solution 2. The PH of abrade fluid is worth in use to should be alkalescent 12~13 between optimal, basic material should be added to adjust later the PH value of abrade mother liquor. Use in original and abrade fluid organic alkaline, the PH value that solution discovers when adjusting PH to be worth increases the result not apparent, its solution is incidental caky, because this experiment considers to use alkalescent older inorganic alkaline solution, solid inorganic alkaline use 1:1go solution of ionic Shui Rong matchs inorganic alkaline solution. Adjust the experimental result that adds cost of PH of inorganic alkaline solution, see a table 2 (scale all is compared for bulk) . Watch 2 adjust the test that adds cost of PH of inorganic alkaline solution is dispersive agent solution 2: PH of inorganic alkaline solution is worth exterior 2:114 solution of ＞ are statified 10:113.

8 solution show maize 20:113.

6 solution show maize 50:112.

2 solution show ivory 100:13.

84 solution show solution of ivory dispersive agent the 2 abrade mother solution that add inorganic alkaline solution are in 10:1~50:1Value of the PH inside limits is stabler, other parameter all does not have big change. Take 16:1chroma serves as mother liquor, join two kinds of activator and a few lubricant. The parameter of two kinds of activator is like graph L quite, 2, 3 are shown. Research discovery adds activator the abrade size of 1 is more clear, the specification adds activator what the corundum in the abrade size of 1 precipitates is more complete, the corundum small pink of float of solution horizontally pivoted hung is fewer, but in light of the effective demand that produces from grind segment, the ability that after we still need to consider abrade size to precipitate again, solution still can shake a corundum small pink -- again dispersive sex. Again dispersive sex is good, can make silicon chip and corundum are contacted adequately, suffer force to make fractional machine rate falls equably, exterior quality rises; Additional, can raise corundum utilization rate, raise abrade rate substantially. The abrade fluid after adding different scale activator to precipitate two days again has jolty discovery, although add different proportional activator 1 abrade and serous superstratum is relatively clear, but the quantity far outclass that it can shake a corundum adds different proportional activator 2 abrade size. Discovery is returned in the process of jolty and abrade size, add different proportional activator 2 abrade size are particularly easy and epispastic, and foamy amount is very large, add different proportional activator so the suspension function photograph of 1 abrade size is compared under better. 2.

4.

The Le Shan that the grind segment effect of 3 different and abrade fluid uses workshop of grind segment of limited company of technology of material of semiconductor of Tianjin annulus Europe to machine is abrade fluid and my school are abrade the silicon chip with abrade fluid, clean lab exceeds to use rice of small accept of eminent human relations in my school microscope of 200 nuclear power has observation. Comparative analysis is knowable: The state of grind segment surface of my school is better. The grain of 4 is much and the graph is concentrated, evenness is spent poorer; Graph the silicon chip surface of 5 delimits little, loss is small, evener. Again my school the silicon chip with abrade abrade fluid is mixed the silicon chip with the silicon chip with abrade abrade fluid and clean clean abrade spirit uses Le Shan metallographic detects layer of exterior condition, injury, comparative figure is graph 6~11 (next graphs all are enlarge 500 times) . Nextpage contrast discovers, the condition of silicon chip surface with abrade abrade fluid should compare my school of the abrade liquid that uses Le Shan and clean clean spirit good, exterior cut is small, crackle is subtler, and another crackle is thick and deep, demonstrative stress is accumulated more serious. Conclusion used inorganic alkaline solution to replace original and abrade fluid in the experiment medium organic alkaline, discover inorganic alkaline solution to be controlled more steadily to value of abrade fluid PH. Should divide powder solution 2: 2=16:1 of inorganic alkaline solution(this scale is eclectic choice) when, tension of value of PH of abrade mother liquor, surface, viscosity is stabler. The basis that alters abrade fluid (dispersive agent, lubricant) the scale of chroma and exterior activator can use change in suspension and dispersive effect. Choose abrade mother liquor: Exterior activator L: Lubricant =94:6: 1Effect of Shi Rong fluid is best. Pass the comparative analysis of condition of pair of silicon chip surface, discover my school is abrade the loss of silicon chip surface with abrade fluid is small, delimit little, flaw is tiny. Pass above experiment analysis, reach chemical part is added in abrade fluid, the mechanical action that becomes onefold is machinery - chemistry, reduced the loss of silicon chip. The academic data of the experimental data of above and conception is worth photograph be identical, because check condition and time limitation, the abrade juice that cannot deserve to compare to above respectively undertakes stress checks an analysis, can detect through metallographic only layer of exterior condition, injury, make qualitative conclusion to exterior stress condition, but in applying production to carry out in limited company of data of semiconductor of red of countryside of the Henan in actual production, exterior position rises apparently, surface roughness drops. Because joined chemistry, manufacturing efficiency raised 15 ％ - 20% , because this was proved,introduce the validity of abrade fluid. CNC Milling