CN201904966U

CN201904966U - Plasma treatment device

Info

Publication number: CN201904966U
Application number: CN2010206363453U
Authority: CN
Inventors: 王俊; 黄智林; 蔡珑元; 解延风
Original assignee: Advanced Micro Fabrication Equipment Inc Shanghai
Current assignee: Medium and Micro Semiconductor Equipment (Shanghai) Co., Ltd.
Priority date: 2010-12-01
Filing date: 2010-12-01
Publication date: 2011-07-20
Anticipated expiration: 2020-12-01

Abstract

A plasma treatment device comprises a reaction cavity provided with a charging and discharging device, and reaction gas is led into the reaction cavity from the top. Radio frequency voltage with high frequency of or above 60MHz is applied to an upper electrode and a lower electrode, and high-frequency discharge is generated after the corresponding electrode is grounded. Or the radio frequency voltage with high frequency of or above 60MHz is applied to a top coil, and the led in reaction gas is ionized into plasma for flocking a silicon wafer. When the plasma treatment device is compared with the prior art mostly using low-frequency flocking, the surface of the silicon wafer is flocked through the radio frequency voltage of or above 60MHz under certain pressure, so that a plasma sheath is thinned, direct-current self-bias is lowered, energy of the plasma bombing the silicon wafer is reduced, damage degree of silicon atomic lattice during bombing process of the silicon wafer is improved greatly, surface damage of the silicon wafer is reduced effectively, and photoelectric conversion efficiency of manufactured solar cells can be improved effectively.

Description

A kind of plasma processing apparatus

Technical field

The utility model relates to a kind of plasma processing apparatus, particularly a kind of plasma processing apparatus that utilizes the plasma source of high frequency.

Background technology

At present, in the process of making solar cell, usually silicon chip is placed on the bottom electrode of reaction chamber of plasma processing apparatus of capacitance coupling type, by between the top electrode of bottom electrode or corresponding setting, forming electric field, the reacting gas ionization of introducing reaction chamber is formed its plasma with it.Or, producing an induction field after feeding alternating current at the some coils of top board arranged outside of the reaction chamber of inductance coupling plasma processing device, the reacting gas of introducing is dissociated forms its plasma.

Plasma by this reacting gas carries out making herbs into wool to silicon chip, promptly remove silicon chip surface since before the damage that produces such as machine cuts, remove the foreign metal ion on surface, and form pyramidal matte at monocrystalline silicon surface, and on polysilicon, form the matte of pit shape, to reduce the reflection of light rate, strengthen absorption to sunlight, and improve photogenerated current density, finally improve the photoelectric conversion efficiency of solar cell.

When radio-frequency voltage being applied on described top electrode or the bottom electrode, can be corresponding in the position of pressing close to top electrode or lower electrode surface, form plasma sheath (sheath); Similar plasma sheath also correspondence is formed in the reaction chamber of described coil below.Because the variation of the electronic response radio-frequency voltage of lighter weight in the plasma can form DC auto-bias Vdc in plasma sheath, and the ion energy distribution in the plasma that incides silicon chip surface is controlled.

The general now following low frequency radio frequency voltage of 60MHz that uses, make big, the DC auto-bias Vdc height of thickness of the plasma sheath of formation, thereby the energy of plasma bombardment silicon chip is excessive, make that the silicon atom lattice of silicon chip surface is destroyed, cause silicon chip surface to produce damage, this is a urgent problem in solar cell making herbs into wool field.

The utility model content

The purpose of this utility model provides a kind of plasma processing apparatus, utilizes the plasma source of high frequency to carry out silicon chip making herbs into wool, reduces the damage of making herbs into wool process to silicon chip surface, thereby improves the photoelectric conversion efficiency of the solar cell of making.

In order to achieve the above object, the technical solution of the utility model provides a kind of plasma processing apparatus, comprises a reaction chamber that is provided with charging/discharging apparatus; The reacting gas that described reaction chamber is introduced after described charging/discharging apparatus ionization, produces plasma to being placed on the silicon chip making herbs into wool in the reaction chamber; The rf frequency that applies on the described charging/discharging apparatus be 60MHz or more than.

In the plasma processing apparatus of capacitance coupling type, described charging/discharging apparatus comprises top electrode and the bottom electrode that correspondence is arranged on described reaction chamber top and bottom; Place the described silicon chip of waiting for making herbs into wool on the described bottom electrode.

Apply high frequency on the described top electrode, corresponding to described bottom electrode ground connection, between described top electrode, bottom electrode, form high-frequency discharge.

Apply high frequency on the described bottom electrode, corresponding to described top electrode ground connection, between described top electrode, bottom electrode, form high-frequency discharge.

On described top electrode or bottom electrode, apply described frequency 60MHz or above high-frequency radio frequency voltage.

The frequency of the described high-frequency radio frequency voltage that applies on described top electrode or bottom electrode is 60MHz, 100MHz or 120MHz.

In the plasma processing apparatus of inductance coupling high formula, described charging/discharging apparatus comprises the some coils that are arranged on described reaction chamber top outer; Be applied with described frequency 60MHz or above high-frequency radio frequency voltage on the described coil, make the position below the corresponding coil in reaction chamber, form the induction field of annular.

The frequency of the described high-frequency radio frequency voltage that applies on the described coil is 60MHz, 100MHz or 120MHz.

Utilize low frequency making herbs into wool to compare with prior art, under suitable pressure, the utility model carries out making herbs into wool by the plasma source of high frequency, can effectively reduce the damage to silicon chip surface, thereby can effectively improve the photoelectric conversion efficiency of the solar cell of making.

Description of drawings

Fig. 1 is a kind of schematic diagram of implementing structure according to the described plasma processing apparatus of a specific embodiment of the present utility model;

Fig. 2 is the schematic diagram according to the described plasma processing apparatus of another specific embodiment of the present utility model.

Embodiment

Below in conjunction with description of drawings embodiment of the present utility model.

Embodiment 1

As Fig. 1 or shown in Figure 2, provide the plasma processing apparatus of capacitance coupling type in the present embodiment, comprise a reaction chamber 10, the top of this reaction chamber 10 and bottom correspondence are provided with top electrode 21 and the bottom electrode 22 that is parallel to each other, wherein the silicon chip 30 that carrying remains the making herbs into wool processing on the bottom electrode 22.

As shown in Figure 1, according to a specific embodiment of the present utility model, on the top electrode 21 of reaction chamber 10, exemplarily apply the high-frequency radio frequency voltage of 60MHz, 100MHz or 120MHz, and with bottom electrode 22 ground connection, make and form top-down high-frequency electric field 41 between the upper/lower electrode, to introduce the reacting gas ionization of reaction chamber 10 from the top by high-frequency discharge, form its plasma, the making herbs into wool processing will be carried out on silicon chip 30 surfaces that are placed on the bottom electrode 22.

As shown in Figure 2, one according to the foregoing description changes example, also can on the bottom electrode 22 of reaction chamber 10, exemplarily apply the high-frequency radio frequency voltage of 60MHz, 100MHz or 120MHz, and with top electrode 21 ground connection, make between the upper/lower electrode and to form from bottom to top high-frequency electric field 42, to introduce the reacting gas ionization of reaction chamber 10 from the top by high-frequency discharge equally, form its plasma, the making herbs into wool processing will be carried out on silicon chip 30 surfaces that are placed on the bottom electrode 22.

Embodiment 2

Provide the plasma processing apparatus of inductance coupling high formula in the present embodiment, comprise a reaction chamber 10, these reaction chamber 10 top outer be provided with some around coil 11.

On this coil 11, exemplarily apply the high-frequency radio frequency voltage of 60MHz, 100MHz or 120MHz, make the position below the corresponding coil 11 in reaction chamber 10, form the induction field of annular, the reacting gas that to introduce from reaction chamber 10 tops dissociates and forms its plasma, and make under this plasma screw, making herbs into wool is carried out on silicon chip 30 surfaces that are placed on reaction chamber 10 bottoms handled.

In sum, utilize low frequency making herbs into wool compared to existing technology, at suitable gas pressure (under as 50 ~ 400mT), the utility model carries out the making herbs into wool of silicon chip surface by 60MHz or above high-frequency radio frequency voltage, make below top electrode or coil, or the less thick of the plasma sheath of bottom electrode top formation, DC auto-bias Vdc reduces, thereby reduced the energy of plasma bombardment silicon chip, thereby the bigger degree of having improved silicon atom lattice damage in the bombardment silicon chip surface process, thereby effectively reduced the damage of silicon chip surface, thereby can effectively improve the photoelectric conversion efficiency of the solar cell of making.

Although content of the present utility model has been done detailed introduction by above preferred embodiment, will be appreciated that above-mentioned description should not be considered to restriction of the present utility model.After those skilled in the art have read foregoing, for multiple modification of the present utility model with to substitute all will be conspicuous.Therefore, protection range of the present utility model should be limited to the appended claims.

Claims

1. a plasma processing apparatus is characterized in that, comprises a reaction chamber (10) that is provided with charging/discharging apparatus; The reacting gas that described reaction chamber (10) is introduced after described charging/discharging apparatus ionization, produces plasma to being placed on silicon chip (30) making herbs into wool in the reaction chamber (10); The rf frequency that applies on the described charging/discharging apparatus be 60MHz or more than.

2. plasma processing apparatus as claimed in claim 1 is characterized in that, described charging/discharging apparatus comprises top electrode (21) and the bottom electrode (22) that correspondence is arranged on described reaction chamber (10) top and bottom; Described bottom electrode (22) is gone up and is placed the described silicon chip (30) of waiting for making herbs into wool.

3. plasma processing apparatus as claimed in claim 2 is characterized in that, described top electrode applies high frequency on (21), and is corresponding to described bottom electrode (22) ground connection, forms high-frequency discharge at described top electrode (21), bottom electrode between (22).

4. plasma processing apparatus as claimed in claim 2 is characterized in that, described bottom electrode applies high frequency on (22), and is corresponding to described top electrode (21) ground connection, forms high-frequency discharge at described top electrode (21), bottom electrode between (22).

5. as claim 3 or 4 described plasma processing apparatus, it is characterized in that, on described top electrode (21) or bottom electrode (22), apply described frequency 60MHz or above high-frequency radio frequency voltage.

6. plasma processing apparatus as claimed in claim 5 is characterized in that, the frequency of the described high-frequency radio frequency voltage that applies on described top electrode (21) or bottom electrode (22) is 60MHz, 100MHz or 120MHz.

7. plasma processing apparatus as claimed in claim 1 is characterized in that, described charging/discharging apparatus comprises the some coils (11) that are arranged on described reaction chamber (10) top outer; Be applied with described frequency 60MHz or above high-frequency radio frequency voltage on the described coil (11), make the position of corresponding coil (11) below in reaction chamber (10), form the induction field of annular.

8. plasma processing apparatus as claimed in claim 7 is characterized in that, the frequency of the described high-frequency radio frequency voltage that applies on the described coil (11) is 60MHz, 100MHz or 120MHz.