阅读说明：本技术 一种酸制绒多晶电池的返工方法 (A kind of reworking method of acid making herbs into wool polycrystalline battery ) 是由 孙腾 缪若文 管高飞 沙忠宇 徐明靖 于 2019-08-29 设计创作，主要内容包括：本发明涉及一种酸制绒多晶电池的返工方法,属于光电技术领域。本发明用于酸制绒多晶返工片的生产,收集制绒、扩散、酸刻蚀、PECVD工序中产生的不良片,针对不同工序产生的返工片进行差异化预处理,随后进行金属催化化学腐蚀法(MCCE)制绒。本发明针对不同工序产生的返工片选择差异性预处理方案,降低返工片表面状态差异,有利于返工片重新制绒后获得均一的绒面。本发明通过MCCE在返工片表面形成200-800纳米级孔洞,进一步经过后道加工工序制备而成的电池,该制绒方法可以大幅度降低硅片表面反射率进而提高光电转换效率,同时可以获得更加均一的绒面,降低色差片比例。(The present invention relates to a kind of reworking methods of sour making herbs into wool polycrystalline battery, belong to field of photoelectric technology.The present invention is used for sour making herbs into wool polycrystalline and does over again the production of piece, collect making herbs into wool, diffusion, acid etch, generate in PECVD process bad, differentiation pretreatment is carried out for the piece of doing over again that different processes generate, then carries out metal catalytic chemical corrosion method (MCCE) making herbs into wool.The present invention is directed to the piece selection differences pretreating scheme of doing over again that different processes generate, and reduction is done over again piece surface state difference, obtains uniform flannelette after the new making herbs into wool of slice weight that is conducive to do over again.The present invention forms 200-800 nanoscale hole hole on piece surface of doing over again by MCCE, the battery being prepared further across rear road manufacturing procedure, the etching method can be greatly lowered silicon chip surface reflectivity and then improve photoelectric conversion efficiency, more uniform flannelette can be obtained simultaneously, reduce color difference piece ratio.)

1. a kind of reworking method of acid making herbs into wool polycrystalline battery, it is characterized in that: doing over again the production of piece for sour making herbs into wool polycrystalline, system is collected Suede, diffusion, acid etch, generate in PECVD process bad, carry out differentiation for the piece of doing over again that different processes generate and locate in advance Reason then carries out MCCE making herbs into wool；

It for the piece of doing over again that making herbs into wool process generates, places it in diffusion furnace and is made annealing treatment, be arranged 450-700 DEG C of temperature, if Time 10-20min, big nitrogen flow 1000-2000mL/min are set, remains on silicon wafer table after removing making herbs into wool for the first time by the pretreatment The organic matter in face, and then match MCCE process for etching；

For the piece of doing over again that diffusing procedure generates, piece surface phosphorosilicate glass of doing over again is removed by HF Solutions Solution, is pre-processed laggard Row MCCE making herbs into wool, the volumetric concentration 2%-5% of HF solution, reaction time 100-150s；

For the piece of doing over again that PECVD process generates, the piece surface SiNx that does over again is removed by HF/HCl mixed acid solution, is pre-processed laggard Row MCCE making herbs into wool, the volumetric concentration 2%-5%, hydrochloric acid volumetric concentration 1%-3%, reaction time 150-300s of HF in mixed liquor.

2. the reworking method of acid making herbs into wool polycrystalline battery as described in claim 1, it is characterized in that: being returned for what acid etch process generated Work piece directly carries out MCCE making herbs into wool without pretreatment.

3. the reworking method of acid making herbs into wool polycrystalline battery as described in claim 1, it is characterized in that: doing over again by differentiation is pretreated Piece passes through MCCE making herbs into wool again；Steps are as follows for MCCE making herbs into wool:

(1) load: pretreated polycrystalline diamond line is done over again piece, is inserted in the making herbs into wool carrying gaily decorated basket；

(2) it pre-processes: polycrystalline diamond line being done over again piece surface polishing using potassium hydroxide solution, removes deacidification making herbs into wool flannelette, hydrogen-oxygen Change potassium mass concentration range 1.2%-4%, 75-85 DEG C of reaction temperature, reaction time 200-480s；

(3) pickling: the silicon wafer after polishing being placed in the hydrofluoric acid solution of volumetric concentration 3%-5%, is neutralized residual in alkali polishing process The lye stayed；

(4) deposition of silver: the silicon wafer after pickling is placed in containing in silver nitrate and hydrofluoric acid mixed solution, deposits one layer in silicon chip surface Argent grain, the volumetric concentration 2%-5% of HF solution, mass concentration containing silver nitrate 0.001%-0.005%, 25-35 DEG C of reaction temperature, instead 60-300s between seasonable；

(5) borehole: the silicon wafer after deposition silver is placed in hydrofluoric acid and hydrogen peroxide mixed solution, nanoscale hole hole suede is formed Face；The volumetric concentration 2%-5% of HF solution, hydrogen peroxide volumetric concentration 0.5%-2.5%, 25-35 DEG C of reaction temperature, reaction time 100- 300s；

(6) desilverization: black silicon wafer is immersed in hydrogen peroxide and ammonium hydroxide mixed solution, removal residual silver nano-grain；In mixed solution Hydrogen peroxide volumetric concentration 0.3%-1.5%, ammonium hydroxide volumetric concentration 0.4%-1.2%, reaction temperature room temperature, reaction time 120-240s；

(7) reaming: the nanoscale hole hole that borehole is formed is expanded into submicron order hole, hydrofluoric acid volume in reaming solution Concentration 3%-8%, nitric acid volumetric concentration 20%-30%, obtains hole aperture 400- by 6-15 DEG C of reaction temperature, reaction time 60-180s The black silicon structure of 700nm；

(8) alkali cleaning: hole surface modification；Hydrogen peroxide volumetric concentration 0.3%-1.5%, ammonium hydroxide volumetric concentration 0.2%-1.2%, hydroxide Potassium concn 1.6%-3.2%, reaction temperature room temperature, reaction time 120-360s；

(9) pickling: neutralizing and remain lye, hydrofluoric acid volume concentration 5%-10%, hydrochloric acid volumetric concentration 1%-3%, reaction temperature room temperature, Reaction time 120-360s；

(10) it washes: removal residual acid solution；

(11) it dries: the silicon wafer after washing is dried with hot nitrogen；85 DEG C of drying temperature, time 480-720s.

Technical field

The present invention relates to a kind of reworking methods of sour making herbs into wool polycrystalline battery, and in particular to a kind of photoelectricity for improving piece of doing over again turn The reworking method for changing efficiency, belongs to field of photoelectric technology.

Background technique

In terms of crystal silicon microtomy, compared with traditional mortar line cutting technology, Buddha's warrior attendant line cutting technology has cutting Speed is fast, cutting liquid is environmentally friendly, low advantage is lost in monolithic.To largely reduce the silicon cost of silicon wafer, the market share It rises year by year, gradually substitutes mortar wire cutting silicon wafer at present.In polycrystalline cell piece technical aspect, polycrystalline diamond wire cutting silicon wafer Have the characteristics that damage is shallow, reflectivity is high, gully structure.By in hydrofluoric acid/nitric acid (HF/HNO₃) auxiliary is added in Woolen-making liquid Agent may be implemented with the comparable flannelette of mortar piece reflectivity, but suede structure difference is obvious, polycrystalline diamond Xian Pian flannelette mechanism edge Gully structure distribution.

Polycrystalline diamond line cell piece process flow at present is as shown in Figure 1, making herbs into wool, diffusion, acid etch, PECVD process can Bad is generated, these bad can be made again polycrystalline cell piece by rework preocess process.Traditional rework preocess process is such as Shown in Fig. 2, wherein prerinse main function is removal SiNx, oxide layer etc., and making herbs into wool main function is the same of removal PN junction again When regenerate flannelette.

Due to HF/HNO₃The characteristics of making herbs into wool system, is: using, as raising point, fault location preferentially corrodes at Defect.Polycrystalline Diamond wire silicon wafer has been removed by making herbs into wool rear surface damaging layer for the first time, piece of doing over again by prerinse and go knot rear surface defect compared with Few, making herbs into wool back reflection rate is higher again, and flannelette size is inhomogenous, causes cell piece incident photon-to-electron conversion efficiency low, and appearance chromatic difference etc. is asked Topic.

Summary of the invention

The purpose of the present invention is overcoming above-mentioned shortcoming, a kind of reworking method of sour making herbs into wool polycrystalline battery is provided, is improved The incident photon-to-electron conversion efficiency of piece of doing over again, while the problems such as solve appearance chromatic difference.

The problems such as in order to improve the incident photon-to-electron conversion efficiency for piece of doing over again, while solve appearance chromatic difference, the present invention develops one kind The reworking method of sour making herbs into wool polycrystalline battery, process of doing over again are done over again the production of piece as shown in figure 3, being suitable for sour making herbs into wool polycrystalline.

The present invention relates to a kind of reworking method of sour making herbs into wool polycrystalline battery, do over again the production of piece for sour making herbs into wool polycrystalline.It should Reworking method carries out differentiation pretreatment for the piece of doing over again that different processes generate.

It for the piece of doing over again that making herbs into wool process generates, places it in diffusion furnace and is made annealing treatment, temperature 450-700 is set DEG C, time 10-20min, big nitrogen flow 1000-2000mL/min are set, remained on after removing making herbs into wool for the first time by the pretreatment The organic matter of silicon chip surface, and then match MCCE process for etching；

For the piece of doing over again that diffusing procedure generates, piece surface phosphorosilicate glass of doing over again, pretreatment are removed by HF Solutions Solution MCCE making herbs into wool, the volumetric concentration 2%-5% of HF solution, reaction time 100-150s are carried out afterwards；

For the piece of doing over again that PECVD process generates, the piece surface SiNx that does over again, pretreatment are removed by HF/HCl mixed acid solution MCCE making herbs into wool is carried out afterwards, the volumetric concentration 2%-5%, hydrochloric acid volumetric concentration 1%-3%, reaction time 150- of HF in mixed liquor 300s。

MCCE making herbs into wool can directly be carried out without pretreatment for the piece of doing over again that acid etch process generates.

The present invention relates to a kind of reworking methods of sour making herbs into wool polycrystalline battery, pass through by the pretreated piece of doing over again of differentiation MCCE making herbs into wool again；Steps are as follows for MCCE making herbs into wool:

(1) load: pretreated polycrystalline diamond line is done over again piece, is inserted in the making herbs into wool carrying gaily decorated basket；

(2) it pre-processes: polycrystalline diamond line being done over again piece surface polishing using potassium hydroxide solution, removes deacidification making herbs into wool flannelette, Potassium hydroxide quality concentration range 1.2%-4%, 75-85 DEG C of reaction temperature, reaction time 200-480s；

(3) pickling: the silicon wafer after polishing being placed in the hydrofluoric acid solution of volumetric concentration 3%-5%, and it is polished to neutralize alkali Remaining lye in journey；

(4) deposition of silver: the silicon wafer after pickling is placed in containing in silver nitrate and hydrofluoric acid mixed solution, is deposited in silicon chip surface One layer of Argent grain, the volumetric concentration 2%-5% of HF solution, the 0.001%-0.005% of mass concentration containing silver nitrate, reaction temperature 25-35 DEG C, reaction time 60-300s；

(5) borehole: the silicon wafer after deposition silver is placed in hydrofluoric acid and hydrogen peroxide mixed solution, nanoscale hole hole is formed Flannelette；The volumetric concentration 2%-5% of HF solution, hydrogen peroxide volumetric concentration 0.5%-2.5%, 25-35 DEG C of reaction temperature, when reaction Between 100-300s；

(6) desilverization: black silicon wafer is immersed in hydrogen peroxide and ammonium hydroxide mixed solution, removal residual silver nano-grain；It mixes molten Hydrogen peroxide volumetric concentration 0.3%-1.5% in liquid, ammonium hydroxide volumetric concentration 0.4%-1.2%, reaction temperature room temperature, reaction time 120-240s；

(7) reaming: the nanoscale hole hole that borehole is formed is expanded into submicron order hole, hydrofluoric acid in reaming solution Volumetric concentration 3%-8%, nitric acid volumetric concentration 20%-30%, 6-15 DEG C of reaction temperature, reaction time 60-180s obtains hole The black silicon structure of aperture 400-700nm；

(8) alkali cleaning: hole surface modification；Hydrogen peroxide volumetric concentration 0.3%-1.5%, ammonium hydroxide volumetric concentration 0.2%- 1.2%, concentration of potassium hydroxide 1.6%-3.2%, reaction temperature room temperature, reaction time 120-360s；

(9) residual lye, hydrofluoric acid volume concentration 5%-10%, hydrochloric acid volumetric concentration 1%-3%, reaction pickling: are neutralized Temperature room temperature, reaction time 120-360s；

(10) it washes: removal residual acid solution；

(11) it dries: the silicon wafer after washing is dried with hot nitrogen；85 DEG C of drying temperature, time 480-720s.

Beneficial effects of the present invention: the present invention is directed to the piece selection differences pretreating scheme of doing over again that different processes generate, Reduction is done over again piece surface state difference, obtains uniform flannelette after the new making herbs into wool of slice weight that is conducive to do over again.The present invention is urged by metal Change chemical corrosion method (MCCE) and form 200-800 nanoscale hole hole on piece surface of doing over again, further across rear road manufacturing procedure system Battery made of standby, the etching method can be greatly lowered silicon chip surface reflectivity and then improve photoelectric conversion efficiency, simultaneously More uniform flannelette can be obtained, color difference piece ratio is reduced.

Detailed description of the invention

Fig. 1 is polycrystalline diamond line cell piece process flow diagram.

Fig. 2 is polycrystalline diamond line cell piece tradition rework preocess flow diagram.

Fig. 3 is polycrystalline diamond line cell piece optimization rework preocess flow diagram.

Fig. 4 is technique flannelette schematic diagram.

A. polycrystalline diamond line flannelette；B. traditional rework preocess flannelette；C. optimize rework preocess flannelette.

Fig. 5 is the flannelette reflectivity of different process scheme preparation.

Specific embodiment