CN206624913U - A kind of PECVD double-sided depositions equipment - Google Patents

Abstract

The utility model discloses a PECVD double-sided deposition equipment, which comprises a feeding area, a heating chamber, a process chamber, a cooling area and a feeding area. The feeding area, the heating chamber, the process chamber, the cooling area and the feeding area are sequential connection; the process chamber is provided with an upper vent plate and a lower vent plate, and a gas source device connected with the upper vent plate and the lower vent plate; the upper vent plate and the lower vent plate are all provided with vent holes, and the upper vent plate and the lower vent plate The lower ventilating plate is arranged in parallel and a passage for accommodating silicon wafers is provided between the two plates; the angle between the plane where the upper ventilating plate or the lower ventilating plate is located and the horizontal plane is 1-5 degrees. By adopting the utility model, film layers can be deposited on the front and back sides of the silicon chip at the same time, thereby reducing the fragmentation rate of the silicon chip and improving production efficiency.

Description

A PECVD double-sided deposition equipment

technical field

The utility model relates to the technical field of solar cells, in particular to a PECVD double-sided deposition equipment.

Background technique

In the photovoltaic solar industry, the manufacture of high-efficiency PERC solar cells must go through seven major processes: texturing, diffusion, etching, coating, screen printing, sintering and annealing. Among them, the purpose of the coating process is to use the method of plasma enhanced chemical vapor deposition to coat aluminum oxide film and silicon nitride film on the back of the silicon wafer, and to coat the silicon nitride film on the front side of the silicon wafer.

At present, the photovoltaic industry mostly adopts tubular PECVD or plate PECVD to coat silicon nitride film on one side of the silicon wafer. Insert the graphite boat or graphite frame, and then put the graphite boat or graphite frame into the furnace tube for coating. The silicon nitride film deposition on the front and back requires two coatings, the process is more complicated, and multiple deposition operations are likely to cause scratches on the silicon wafer, increasing the fragmentation rate, which is not conducive to reducing the defective rate of the product.

Contents of the invention

The technical problem to be solved by the utility model is to provide a PECVD double-sided deposition equipment, which can simultaneously deposit film layers on the front and back sides of silicon wafers, reduce the fragmentation rate of silicon wafers, and improve production efficiency.

In order to solve the above technical problems, the utility model provides a PECVD double-sided deposition equipment, including a feeding area, a heating chamber, a process chamber, a cooling area and a feeding area, the feeding area, heating chamber, process chamber, cooling The area and the unloading area are connected in sequence; the process chamber is provided with an upper ventilation plate and a lower ventilation plate, and a gas source device communicated with the upper ventilation plate and the lower ventilation plate;

Both the upper ventilation plate and the lower ventilation plate are provided with ventilation holes, the upper ventilation plate and the lower ventilation plate are arranged in parallel and a passage for accommodating silicon wafers is provided between the two plates;

The angle formed between the plane where the upper ventilation plate or the lower ventilation plate is located and the horizontal plane is 1-5 degrees.

As an optimal technical solution of the PECVD double-sided deposition equipment, the upper ventilation plate is provided with 100-500 ventilation holes, and the diameter of the ventilation holes is 1-10mm; the lower ventilation plate is provided with 100-500 ventilation holes, The diameter of the ventilation hole is 1-10mm.

As a preferred technical solution of the PECVD double-sided deposition equipment, the ventilation holes of the upper ventilation plate are arranged in a square array, and the spacing of the ventilation holes is 1-10mm; the ventilation holes of the lower ventilation plate are arranged in a square matrix, The spacing of the ventilation holes is 1-10mm.

As a preferred technical solution of the PECVD double-sided deposition equipment, the arrangement and spacing of the vent holes of the upper vent plate and the vent holes of the lower vent plate are the same.

As the preferred technical scheme of the PECVD double-sided deposition equipment, the gas source device is provided with an ammonia gas tank and a silane gas tank, and the ammonia gas tank and the silane gas tank are communicated with the upper ventilation plate through a conduit; the ammonia gas tank and the silane gas tank are connected through a conduit; The silane gas tank communicates with the lower ventilation plate through a conduit.

As a preferred technical solution of the PECVD double-sided deposition equipment, the vent hole is provided with a first vent hole and a second vent hole, the first vent hole communicates with the ammonia gas tank, and the second vent hole communicates with the silane gas tank.

As a preferred technical solution of the PECVD double-sided deposition equipment, the upper ventilation plate and the lower ventilation plate are made of quartz plates.

As a preferred technical solution of the PECVD double-sided deposition equipment, the distance between the upper ventilation plate and the lower ventilation plate is 50-300 mm.

Implementation of the utility model embodiment has the following beneficial effects:

The PECVD double-sided deposition equipment described in the utility model changes the structure in the process chamber on the basis of the existing PECVD equipment, so that the silicon wafer is suspended between the two plates under the action of the gas sprayed from the upper and lower two ventilation plates. Under the condition of high temperature and high pressure, the injected ammonia gas and silane gas react with the silicon wafer to deposit silicon nitride film on the front and back of the silicon wafer at the same time, reduce the number of repeated depositions, improve production efficiency, and reduce the fragmentation rate; and multiple times The deposition operation is easy to cause scratches on the surface of the silicon wafer, so the use of the PECVD double-sided deposition equipment of the utility model can reduce the damage to the silicon wafer, improve the product qualification rate, and the product performance is more stable and reliable.

Description of drawings

Fig. 1 is the structural representation of a kind of PECVD double-sided deposition equipment of the present utility model;

Fig. 2 is a schematic diagram of the ventilation hole arrangement of a kind of PECVD double-sided deposition equipment of the present invention;

Fig. 3 is a schematic diagram of another ventilation hole arrangement of a PECVD double-sided deposition equipment of the present invention.

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings.

In the existing PECVD equipment, the silicon wafer is placed on a graphite boat and sent into the reaction chamber, and the gas inlet pipe sprays the reaction gas into the reaction chamber, thereby coating the exposed side of the silicon wafer with a film layer. However, as researchers have gradually deepened their research on the performance of solar cells, for example, PERC solar cells need to be coated with aluminum oxide film and silicon nitride film on the back of the silicon wafer, and coated with silicon nitride film on the front side of the silicon wafer. Three times of deposition and film formation are required in the process. Not only the steps are repeated and cumbersome, but also it is easy to cause scratches on the silicon wafer, and it is difficult to control the defective rate of the product.

According to the characteristics of the above-mentioned PERC solar cell, the inventors of the present invention have found that the front and back of the cell need to be coated with a layer of silicon nitride film, and the process conditions such as reaction gas, temperature, and pressure are the same, so if the existing PECVD can be modified The equipment makes it possible to deposit silicon nitride film on the front and back of the silicon wafer at the same time, which can save the time and process of redeposition, improve production efficiency, and reduce the fragmentation rate; moreover, multiple deposition operations are easy to cause scratches on the silicon wafer. Therefore, the use of the PECVD double-sided deposition equipment of the utility model can reduce the damage to the silicon wafer, improve the qualified rate of the product, and the product performance is more stable and reliable.

As shown in Figure 1, the utility model provides a PECVD double-sided deposition equipment, including a feeding area 1, a heating chamber 2, a process chamber 3, a cooling area 4 and a feeding area 5, the feeding area 1, the heating chamber 2. The process chamber 3, the cooling zone 4 and the feeding zone 5 are sequentially connected; the process chamber 3 is provided with an upper ventilating plate 6 and a lower ventilating plate 7, and a gas source device communicating with the upper ventilating plate 6 and the lower ventilating plate 7 8;

The upper ventilating plate 6 and the lower ventilating plate 7 are all provided with air holes, the upper ventilating plate 6 and the lower ventilating plate 7 are arranged in parallel and a passage for accommodating the silicon chip 9 is provided between the two plates;

The angle formed between the plane where the upper ventilation plate 6 or the lower ventilation plate 7 is located and the horizontal plane is 1-5 degree.

The feeding area 1 of the PECVD double-sided deposition equipment described in the utility model is equipped with a feeding machine so that the silicon wafer 9 is automatically sent into the heating chamber 2 for preheating, and then passes through the upper ventilation plate 6 and the lower ventilation plate 7 of the process chamber 3 In between, the reaction gas is sprayed at the top and bottom of the silicon wafer 9 at the same time, and the silicon wafer 9 is suspended between the upper ventilation plate 6 and the lower ventilation plate 7 through the adjustment of the gas flow rate. A silicon nitride film is formed on the back side at the same time. Since the upper ventilating plate 6 and the lower ventilating plate 7 are arranged obliquely, under the joint action of gravity and the impact force of the upper and lower airflows, the silicon wafer 9 slowly advances from the entrance of the passage to the exit of the passage, and passes through the cooling zone 4 after being cooled. , unloaded from the PECVD double-sided deposition equipment described in the utility model by a blanking machine.

It should be noted that the upper vent plate 6 and the lower vent plate 7 of the utility model are provided with dense vent holes, preferably, the upper vent plate 6 and the lower vent plate 7 are each provided with 100-500 vent holes, according to the spray Gas flow rate requirements can choose a vent hole with a diameter of 1-10mm.

In addition, the ventilation holes of the upper ventilation plate 6 are arranged in a square array, and the spacing of the ventilation holes is 1-10 mm; the ventilation holes of the lower ventilation plate 7 are arranged in a square matrix, and the spacing of the ventilation holes is 1-10 mm. Preferably, the ventilation holes of the upper ventilation plate 6 and the ventilation holes of the lower ventilation plate 7 have the same arrangement and spacing, so as to facilitate the calculation of the stress on the silicon wafer 9 .

Forming a silicon nitride film on the silicon wafer 9 needs to pass into two kinds of reaction gases, ammonia and silane. Therefore, the gas source device 8 is provided with an ammonia gas tank and a silane gas tank. The air tank is connected, and silane is sprayed downward, and the flow rate of silane is 1500-1800 sccm; the other part of the vent hole of the upper ventilation plate 6 is connected with the ammonia gas tank, and ammonia gas is sprayed downward, and the flow rate of ammonia gas is 4000-10000 sccm. A part of the ventilation hole of the lower ventilation plate 7 is connected with the silane gas tank, and silane is sprayed upwards, and the flow rate of the silane is 1800-3000 sccm. 12000 sccm. For ease of description, the vent hole is divided into the first vent hole 10 and the second vent hole 11 below, the first vent hole 10 communicates with the ammonia gas tank, and sprays ammonia; the second vent hole 11 communicates with the silane gas tank, and sprays silane .

Because the flow rates of ammonia and silane are different, the first vent hole 10 and the second vent hole 11 need to be arranged at intervals in the setting of the vent holes, so that the silicon wafer is evenly stressed. Two implementations are provided below:

Embodiment 1, as shown in Figure 2, the first ventilation holes 10 are arranged in a row (referred to as "one row"), and the second ventilation holes 11 are arranged in a row (referred to as "two rows"). Column-one column-two columns are arranged at intervals to form a square array of ventilation holes.

Embodiment 2, as shown in Figure 3, the positions of the first vent hole 10 are all set as the second vent hole 11, and correspondingly, the positions of the second vent hole 11 are all set as the first vent hole 10, by This regular arrangement forms a square array of air holes.

Using the above two implementations to arrange the air holes can make the gas concentration sprayed by the upper air plate 6 and the lower air plate 7 more uniform, and the impact force on the silicon wafer is different due to the different gas flow rates of ammonia and silane. The settings can minimize the impact of the gas flow rate on the stress on the silicon wafer.

It should be noted that the upper ventilating plate 6 and the lower ventilating plate 7 of the utility model are made of quartz plates, and the distance between the upper ventilating plate 6 and the lower ventilating plate 7 is 50-300 mm, so that the silicon chip can be placed between the two plates. pass between.

In summary, the PECVD double-sided deposition equipment described in this utility model changes the structure in the process chamber on the basis of the existing PECVD equipment, so that the silicon wafer is suspended on the two sides under the action of gas injection from the upper and lower two ventilation plates. Between the plates, under the condition of high temperature and high pressure, the injected ammonia gas and silane gas react with the silicon wafer to deposit silicon nitride film on the front and back of the silicon wafer at the same time, reducing the number of repeated depositions and improving production efficiency; and more Repeated deposition operations are likely to cause scratches on silicon wafers, so the use of the PECVD double-sided deposition equipment of the utility model can reduce damage to silicon wafers, improve product qualification rate, and make product performance more stable and reliable.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model rather than limiting the protection scope of the present utility model. Although the utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art It should be understood that the technical solution of the utility model can be modified or equivalently replaced without departing from the essence and scope of the technical solution of the utility model.

Claims (8)

1. A kind of PECVD double-sided deposition equipment is characterized in that, comprises loading area, heating cavity, process chamber, cooling zone and blanking area, described loading area, heating cavity, process cavity, cooling zone and blanking area connected in sequence; the process chamber is provided with an upper ventilation plate and a lower ventilation plate, and a gas source device communicating with the upper ventilation plate and the lower ventilation plate; Both the upper ventilation plate and the lower ventilation plate are provided with ventilation holes, the upper ventilation plate and the lower ventilation plate are arranged in parallel and a passage for accommodating silicon wafers is provided between the two plates; The angle formed between the plane where the upper ventilation plate or the lower ventilation plate is located and the horizontal plane is 1-5 degrees. 2. PECVD double-sided deposition equipment as claimed in claim 1, is characterized in that, described upper aeration plate is provided with 100-500 air holes, and the diameter of air hole is 1-10mm; Described lower aeration plate is provided with 100-500 air holes. 500 vent holes, the diameter of the vent holes is 1-10mm. 3. PECVD double-sided deposition equipment as claimed in claim 1, is characterized in that, the ventilation hole of described upper ventilation plate is arranged in square array, and the spacing of ventilation hole is 1-10mm; The ventilation hole of described lower ventilation plate is with Arranged in a square array, the spacing of the ventilation holes is 1-10mm. 4 . The PECVD double-sided deposition equipment according to claim 3 , wherein the ventilation holes of the upper ventilation plate and the ventilation holes of the lower ventilation plate have the same arrangement and spacing. 5. PECVD double-sided deposition equipment as claimed in claim 1, is characterized in that, described gas source device is provided with ammonia gas tank and silane gas tank, and ammonia gas tank and silane gas tank communicate with upper ventilation plate through conduit; The ammonia gas tank and the silane gas tank are communicated with the lower ventilation plate through conduits. 6. PECVD double-sided deposition equipment as claimed in claim 5, is characterized in that, vent hole is provided with first vent hole and second vent hole, and the first vent hole is communicated with ammonia gas tank, and the second vent hole is connected with silane gas tank. Tank connected. 7. The PECVD double-sided deposition equipment according to claim 1, wherein the upper ventilation plate and the lower ventilation plate are made of quartz plates. 8. The PECVD double-sided deposition equipment according to claim 1, wherein the distance between the upper ventilation plate and the lower ventilation plate is 50-300mm.