TWI492410B - Semiconductor device and manufacturing method thereof - Google Patents

Description

Semiconductor device and method of manufacturing same

The present invention relates to a semiconductor device and a method of fabricating the same, and more particularly to a semiconductor device having a three-layer structure to form a current-conducting mechanism of a transparent conductive film and a method of fabricating the same.

In recent years, as the problem of environmental pollution has become more and more serious, many countries have begun to develop new green energy sources to reduce environmental pollution. Solar cells can convert the sun's light energy into electrical energy, and this conversion does not produce any polluting substances, so solar cells are gradually gaining attention. In order to increase the light receiving area of the solar cell, the positive electrode and the negative electrode of the solar cell can be disposed on the backlight surface of the solar cell, which is an interdigitated back contact (IBC) solar cell.

1 is a schematic cross-sectional view of a conventional semiconductor device for a fork-shaped back electrode solar cell. The semiconductor device 100 has a semiconductor substrate 110, and the semiconductor substrate 110 has a p-type doping on a side adjacent to the backlight surface 110a. The impurity region 111 and the n-type doping region 112 are connected to the metal layer 150 to serve as a positive electrode and a negative electrode of the semiconductor device 100, respectively.

The manufacturing method of the conventional semiconductor device 100 precedes the backlight of the semiconductor substrate 110. A protective layer 120 is formed on the face 110a, and an opening 121 of the protective layer 120 is formed to expose a portion of the p-type doped region 111 and the n-type doped region 112. Next, a metal layer 150 is deposited to cover the protective layer 120 and the exposed p-type doped region 111 and the n-type doped region 112, thereby contacting the metal layer 150 with the p-type doped region 111 and the n-type doped region 112. Finally, an opening 151 is formed in the metal layer 150 to separately contact the metal layer of the p-type doping region 111 and the metal layer contacting the n-type doping region 112.

However, in this manufacturing method, the hole opening process is a necessary step. Therefore, the control of the opening size, whether the portion of the protective layer to be removed and the metal layer remain, and the integrity of the opening pattern, etc., will affect the quality of the semiconductor device 100. In addition, the opening process also tends to cause the passivation effect of the protective layer 120 on the semiconductor substrate 110 to be deteriorated.

In view of the above-mentioned problems of the prior art, it is an object of the present invention to provide a semiconductor device for reducing the hole opening process and a method of fabricating the same, which avoids the problems of the prior art.

In order to achieve the above object, the present invention provides a method of fabricating a semiconductor device, comprising the steps of: providing a semiconductor substrate having a first major surface, and the semiconductor substrate having a plurality of sides adjacent to the first major surface a doped region; a first oxide layer is formed on the first main surface of the semiconductor substrate; a first metal pattern layer is formed on the first oxide layer, and a pattern shape of the first metal pattern layer projected onto the first main surface is included in a region of the doped region in the semiconductor substrate; forming a second oxide layer covering the first oxide layer and the first metal pattern layer; and forming a pattern shape directly on the second oxide layer by using an electroplating process corresponding to the first metal pattern layer a second metal pattern layer.

Wherein, the method of fabricating the semiconductor device of the present invention may remove the native oxide on the first major surface before forming the first oxide layer.

Wherein, the semiconductor device of the present invention may be a finger-shaped back electrode solar cell or other photovoltaic semiconductor device, and the semiconductor device in the semiconductor device of the present invention further has a second main surface relative to the first main surface, wherein The method of fabricating a semiconductor device of the invention further includes forming an anti-reflective layer on the second major surface of the semiconductor substrate.

Wherein, the thickness of the first oxide layer is less than 5 nm, the thickness of the first metal pattern layer is between 15 nm and 20 nm, and the thickness of the second oxide layer is between 10 nm and 20 nm.

The material of the first metal pattern layer may be aluminum, gold, silver, copper, titanium or other metals or alloys having good electrical conductivity. In addition, the material of the first oxide layer may be ceria, yttria, titania, zinc oxide, aluminum oxide, tin dioxide or other suitable oxide, and the material of the second oxide layer may be ceria, yttrium oxide, Titanium dioxide, zinc oxide, aluminum oxide, tin dioxide or other suitable oxides. Also, the material of the second oxide layer may be the same as the material of the first oxide layer.

Therefore, the manufacturing method of the semiconductor device of the present invention can form a current conduction mechanism of a transparent conductive film by a three-layer structure, thereby reducing the opening process, thereby reducing the process error caused by the opening process. In addition, the method for fabricating the semiconductor device of the present invention may be formed by sequentially forming a first oxide layer, a first metal pattern layer and a second oxide layer on the first main surface of the semiconductor substrate to form a transparent conductive film. a current conduction mechanism, whereby a second metal pattern layer that is formed in a pattern shape projected onto the first main surface and included in a region of the doped region is directly formed, and the second metal pattern layer is directly connected to the doped region via the opening, The semiconductor device of the present invention can be completed .

Furthermore, the present invention further provides a semiconductor device such as a forked back electrode solar cell or other photovoltaic semiconductor device. The semiconductor device of the present invention comprises: a semiconductor substrate having a first main surface and a second main surface, wherein the semiconductor substrate has a plurality of doped regions on a side adjacent to the first main surface; the first oxide layer, Formed on the first main surface of the semiconductor substrate; the first metal pattern layer is formed on the first oxide layer, and the pattern shape of the first metal pattern layer projected onto the first main surface is doped in the semiconductor substrate a region of the region; a second oxide layer covering the first oxide layer and the first metal pattern layer; a second metal pattern layer formed on the second oxide layer, wherein the pattern shape of the second metal pattern layer corresponds to the first a pattern shape of the metal pattern layer; and an anti-reflection layer formed on the second main surface of the semiconductor substrate.

Wherein, the thickness of the first oxide layer is less than 5 nm, the thickness of the first metal pattern layer is between 15 nm and 20 nm, and the thickness of the second oxide layer is between 10 nm and 20 nm.

The material of the first metal pattern layer may be aluminum, gold, silver, copper, titanium or other metals or alloys having good electrical conductivity. In addition, the material of the first oxide layer may be ceria, yttria, titania, zinc oxide, aluminum oxide, tin dioxide or other suitable oxide, and the material of the second oxide layer may be ceria, yttrium oxide, Titanium dioxide, zinc oxide, aluminum oxide, tin dioxide or other suitable oxides. Also, the material of the second oxide layer may be the same as the material of the first oxide layer.

Therefore, one of the semiconductor devices of the present invention is characterized in that a current conducting machine such as a transparent conductive film is formed by a first oxide layer, a first metal pattern layer and a second oxide layer. The second metal pattern layer can be directly formed in the region of the doped region, and the second metal pattern layer can be directly connected to the doped region via the opening. An electrode of a semiconductor device of the invention.

In summary, the semiconductor device and the method of fabricating the same according to the present invention may have one or more of the following advantages:

(1) forming a first oxide layer, a first metal pattern layer, and a second oxide layer by sequentially stacking on the first main surface of the semiconductor substrate to jointly form a current conduction mechanism of the transparent conductive film, thereby directly forming a projection The semiconductor device of the present invention can be completed by the pattern shape of the first main surface including the second metal pattern layer in the region of the doped region, and the second metal pattern layer is directly connected to the doped region via the opening.

(2) forming a current conduction mechanism of the transparent conductive film by the first oxide layer, the first metal pattern layer and the second oxide layer, thereby avoiding the use of the hole opening process in the manufacture of the semiconductor device, thereby avoiding the hole opening process The resulting process error.

100‧‧‧Semiconductor device

110‧‧‧Semiconductor substrate

110a‧‧‧Backlight

111‧‧‧p-doped region

112‧‧‧n-doped area

120‧‧‧Protective layer

121‧‧‧ openings

150‧‧‧metal layer

151‧‧‧ openings

200‧‧‧Semiconductor device

210‧‧‧Semiconductor substrate

210a‧‧‧ first major surface

210b‧‧‧second main surface

211‧‧‧n-doped region

211A‧‧‧Area

212‧‧‧p-doped region

212A‧‧‧Area

213‧‧‧ interval zone

220‧‧‧First oxide layer

230‧‧‧First metal pattern layer

231‧‧‧First n-type corresponding metal pattern

232‧‧‧The first p-type corresponding metal pattern

240‧‧‧Second oxide layer

250‧‧‧Second metal pattern layer

251‧‧‧Second n-type corresponding metal pattern

251a‧‧‧pattern shape

252‧‧‧Second p-type corresponding metal pattern

252a‧‧‧pattern shape

261‧‧‧protection layer

262‧‧‧Anti-reflective layer

910-950‧‧‧Steps

1 is a schematic cross-sectional view of a semiconductor device of a conventional finger-shaped back electrode solar cell.

Figure 2-4 is a partial cross-sectional view showing the process of the semiconductor device of the present invention.

Fig. 5 is a partial cross-sectional view showing the semiconductor device of the present invention.

Figure 6 is a partial bottom plan view of the semiconductor device of the present invention.

Fig. 7 is a flow chart showing a method of manufacturing a semiconductor device of the present invention.

Please refer to FIG. 2 to FIG. 7 , and FIG. 2-4 is a process of the semiconductor device of the present invention. 5 is a schematic cross-sectional view of a semiconductor device of the present invention, FIG. 6 is a partial bottom view of the semiconductor device of the present invention, and FIG. 7 is a flow chart of a method for fabricating the semiconductor device of the present invention.

As shown in FIGS. 2 to 7, the method of fabricating the semiconductor device 200 of the present invention first provides a semiconductor substrate 210 (step 910), wherein the semiconductor substrate 210 has a first major surface 210a adjacent to the first major surface 210a. One side has a plurality of doped regions (such as an n-type doped region 211 and a p-type doped region 212). The semiconductor device 200 in this embodiment is a finger-shaped back electrode solar cell. The first main surface 210a of the semiconductor substrate 210 is a backlight surface of the solar cell, and the semiconductor substrate 210 has a side adjacent to the first main surface 210a. A plurality of doped regions (such as an n-type doped region 211 and a p-type doped region 212). The doped regions of the same polarity may be connected to each other or divided into a plurality of small regions that are not connected to each other. It should be particularly noted that the semiconductor substrate 210 itself may also contain a dopant, but the doping region mentioned in the context of the specification means that the doping concentration of the region is greater than the background doping concentration of the substrate 210, or The polarity of the dopant of the region is different from the polarity of the background dopant of the semiconductor substrate 210. In addition, the doped regions (such as the n-type doping region 211 and the p-type doping region 212) may have a spacer region 213, and the doping concentration of the spacer region 213 is equivalent to the background of the semiconductor substrate 210. The doping concentration, or the polarity of the spacer 213 is the same as the polarity of the background dopant of the semiconductor substrate 210.

In addition, the semiconductor substrate 210 of the semiconductor device 200 of the present invention may have, for example, a second main surface 210b opposite to the first main surface 210a, and the method of fabricating the semiconductor device 200 of the present invention may form an anti-deformation after the semiconductor substrate 210 is provided. The reflective layer 262 is on the second major surface 210b. For example, the second main surface 210b of the semiconductor substrate 210 can be, for example, a light receiving surface of a fork-shaped back electrode solar cell, and thus can be half The protective layer 261 and the anti-reflective layer 262 are sequentially stacked on the second main surface 210b of the conductor substrate 210, thereby increasing the absorption amount of light by the semiconductor device 200 of the present invention. In addition, the semiconductor substrate 210 provided in step 910 may have a protective layer 261 and an anti-reflection layer 262.

After the semiconductor substrate 210 is provided (step 910), the manufacturing method of the semiconductor device 200 of the present invention forms the first oxide layer 220 on the first main surface 210a of the semiconductor substrate 210 (step 920), thereby protecting the semiconductor substrate 210 and the semiconductor. The n-type doping region 211 and the p-type doping region 212 in the substrate 210. The material of the semiconductor substrate 210 is, for example, a single crystal germanium or a polycrystalline germanium. The material of the first oxide layer 220 may be, for example, hafnium oxide (SiO2), silicon oxide, titanium oxide (TiO2), zinc oxide (ZnO), oxidation. Aluminum (such as Al2O3), tin dioxide (SnO2) or other suitable oxide. The first oxide layer 220 has a certain passivation effect on the semiconductor substrate 210, but the thickness of the first oxide layer 220 is preferably less than 5 nm so as not to affect the overall conductivity of the semiconductor device 200. For example, the manufacturing method of the semiconductor device 200 of the present invention may form the germanium dioxide or hafnium oxide on the semiconductor substrate 210 by thermal oxidation, for example, after removing the native oxide on the first main surface 210a of the semiconductor substrate 210. Forming an oxide on the first major surface of the semiconductor substrate 210 on the first main surface 210a or by physical vapor phase deposition (PVD) or chemical vapor deposition (CVD) The first oxide layer 220 is formed on the first main surface 210a of the semiconductor substrate 210 by 210a.

Next, after the step 920, the manufacturing method of the semiconductor device 200 of the present invention forms the first metal pattern layer 230 on the first oxide layer 220 (step 930), and the first metal pattern layer 230 is projected onto the first main surface 210a. The pattern shape is included in the n-type doping region The region between the 211 and the p-doped region 212 is common. The pattern shape of the first metal pattern layer 230 may correspond to a region where the n-type doping region 211 and the p-type doping region 212 are common. Further, the material of the first metal pattern layer 230 may be, for example, aluminum (Al), gold (Au), silver (Ag), copper (Cu), titanium (Ti), or other metals or alloys having good electrical conductivity. Moreover, the thickness of the first metal pattern layer 230 is preferably between 15 nanometers (nm) and 20 nanometers, thereby forming a continuous film which is relatively complete in conductivity and which does not affect subsequent processes.

For example, after step 920, the method of fabricating the semiconductor device 200 of the present invention can utilize, for example, a metal mask in conjunction with physical vapor deposition to effect regionalized thin film metal deposition. The size of the opening position of the metal mask projected onto the first main surface 210a is included in a region formed by the n-type doping region 211 and the p-type doping region 212. Therefore, in the manufacturing method of the semiconductor device 200 of the present invention, the first n-type corresponding metal pattern 231 and the first p-type corresponding metal pattern 232 may be formed in step 930, and the first n-type corresponding metal pattern 231 corresponds to the first p-type. The pattern shapes projected onto the first main surface 210a by the metal pattern 232 are respectively included in the regions of the n-type doping region 211 and the p-type doping region 212, and the first n-type corresponding metal patterns 231 and the first The p-type corresponding metal patterns 232 collectively constitute the first metal pattern layer 230.

After the step 930, the manufacturing method of the semiconductor device 200 of the present invention forms the second oxide layer 240 to cover the first metal pattern layer 230 and the exposed first oxide layer 220 (step 940). The thickness of the second oxide layer 240 is preferably between 10 nm and 20 nm, and the material of the second oxide layer 240 may be ceria, yttria, titania, zinc oxide, or aluminum oxide. Al2O3), tin dioxide or other suitable oxide. Also, the material of the second oxide layer 240 may be the same or different from the material of the first oxide layer 220. For example, in step 940, physical vapor deposition or A process technique such as chemical vapor deposition to form a second oxide layer 240 covering the first metal pattern layer 230 and the first oxide layer 220. The three-layer structure of the first oxide layer 220, the first metal pattern layer 230 and the second oxide layer 240 can jointly form a current conduction mechanism of the transparent conductive film, and the surface resistivity of the three-layer structure is as low as 10-4. -10-5 ohm centimeters (Ω ‧ cm).

Then, after the step 940, the manufacturing method of the semiconductor device 200 of the present invention directly forms the second metal pattern layer 250 corresponding to the first metal pattern layer 230 by using an electroplating process (step 950), thereby avoiding the opening process. And the resulting process error. For example, in step 950, the foregoing three-layer structure can be connected to a potential and placed in a plating bath, whereby the second n-type corresponding metal is plated at a specific position by the conductivity of different regions of the three-layer structure. The pattern 251 and the second p-type corresponding metal pattern 252 together constitute the second metal pattern layer 250. In other words, since the region corresponding to the pattern shape of the first metal pattern layer 230 has better conductivity with respect to other regions, the second metal pattern layer 250 can be directly plated on the pattern corresponding to the first metal pattern layer 230. On the second oxide layer 240 on the shape of the shape, a second metal pattern layer 250 having a pattern shape corresponding to the pattern shape of the first metal pattern layer 230 is formed. The pattern shape of the first metal pattern layer 230 projected onto the first main surface 210a is included in a region where the n-type doping region 211 and the p-type doping region 212 are formed together, so the second metal pattern layer 250 is projected. The pattern shape to the first main surface 210a is also included in a region where the n-type doping region 211 and the p-type doping region 212 are formed together.

For example, the pattern shape 251a projected onto the first main surface 210a by the second n-type corresponding metal pattern 251 is included in the region 211A of the n-type doping region 211, and the second p-type corresponding metal pattern 252 is projected onto the first main The pattern shape 252a of the surface 210a is included in the blend In the region 212A of the impurity region 212, the first n-type corresponding metal pattern 231 and the second n-type corresponding metal pattern 251 together constitute an external electrode of the n-type doping region 211, and the first p-type corresponding metal pattern 232 is formed. And the second p-type corresponding metal pattern 252 together constitute an external electrode of the p-type doping region 212. And in order to separately derive currents in the n-type doped regions 211 and the p-type doped regions 212 having different polarities, the second n-type corresponding metal patterns 251 and the second p-type corresponding metal patterns 252 are separated from each other.

In summary, the manufacturing method of the semiconductor device 200 of the present invention can form a current conduction mechanism of a transparent conductive film by a three-layer structure to avoid a hole opening process, thereby avoiding a process error caused by a hole opening process. Furthermore, the manufacturing method of the semiconductor device 200 of the present invention can form a current conduction mechanism of a transparent conductive film by a three-layer structure, whereby a pattern shape directly projected onto the first main surface 210a is included in the doped region. The semiconductor device 200 of the present invention can be completed by the second metal pattern layer 250 in the region, and the second metal pattern layer 250 is directly connected to the doped region via the opening.

Therefore, the semiconductor device 200 of the present invention may be, for example, a photovoltaic semiconductor device such as a fork-shaped back electrode solar cell. The semiconductor device 200 of the present invention may include a semiconductor substrate 210, a first oxide layer 220, a first metal pattern layer 230, a second oxide layer 240, a second metal pattern layer 250, and an anti-reflection layer 262. The semiconductor substrate 210 has a corresponding first main surface 210a and second main surface 210b. For example, the first major surface 210a and the second major surface 210b may be a backlight surface and a light receiving surface of the interdigitated back electrode solar cell. Moreover, the semiconductor substrate 210 may have a plurality of doped regions (such as an n-type doped region 211 and a p-type doped region 212) on a side adjacent to the first main surface 210a.

In other words, the first oxide layer 220 is formed on the first main surface of the semiconductor substrate 210. The first metal pattern layer 230 is formed on the first oxide layer 220, and the pattern shape projected onto the first main surface 210a by the first metal pattern layer 230 is included in a region where the doped regions are formed together. In addition, the second oxide layer 240 covers the first oxide layer 220 and the first metal pattern layer 230, and the second metal pattern layer 250 is formed on the second oxide layer 240, and the pattern shape of the second metal pattern layer 250 is Corresponding to the pattern shape of the first metal pattern layer 230. In other words, the pattern shape projected onto the first main surface 210a by the second metal pattern layer 250 is included in a region where the doped regions are formed together. In addition, a multi-layer structure of the protective layer 261 and the anti-reflection layer 262 may be sequentially stacked on the second main surface 210b of the semiconductor substrate 210.

The material of the first oxide layer 220 may be, for example, hafnium oxide, hafnium oxide, titanium dioxide, zinc oxide, aluminum oxide (such as aluminum oxide), tin dioxide or other suitable oxide, and the first metal pattern layer 230 The material may be, for example, aluminum, gold, silver, copper, titanium or other metal with good conductivity, and the material of the second oxide layer 240 may be, for example, cerium oxide, cerium oxide, titanium dioxide, zinc oxide, aluminum oxide (such as trioxide). Alluminium), tin dioxide or other suitable oxide. Also, the material of the second oxide layer 240 may be the same or different from the material of the first oxide layer 220.

In addition, in the semiconductor device 200 of the present invention, the first oxide layer 220, the first metal pattern layer 230, and the second oxide layer 240 are used to collectively form a three-layer structure of a transparent conductive film, and thus the first oxide layer 220 Preferably, the thickness of the first metal pattern layer 230 is between 15 nm and 20 nm, and the thickness of the second oxide layer 240 is preferably between 10 nm and 20 nm. Between 20 nm.

Therefore, one of the features of the semiconductor device 200 of the present invention is that the first oxide layer 220, the first metal pattern layer 230 and the second oxide layer 240 together form a current conduction mechanism of the transparent conductive film, thereby directly forming a projection to Diagram of the first major surface 210a The shape of the second metal pattern layer 250 is included in the region of the doped region, and the second metal pattern layer 250 is directly connected to the doped region via the opening to form an electrode of the semiconductor device 200 of the present invention.

The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

200‧‧‧Semiconductor device

210‧‧‧Semiconductor substrate

210a‧‧‧ first major surface

210b‧‧‧second main surface

211‧‧‧n-doped region

212‧‧‧p-doped region

213‧‧‧ interval zone

220‧‧‧First oxide layer

230‧‧‧First metal pattern layer

231‧‧‧First n-type corresponding metal pattern

232‧‧‧The first p-type corresponding metal pattern

240‧‧‧Second oxide layer

250‧‧‧Second metal pattern layer

251‧‧‧Second n-type corresponding metal pattern

252‧‧‧Second p-type corresponding metal pattern

261‧‧‧protection layer

262‧‧‧Anti-reflective layer

Claims (6)

A method of fabricating a semiconductor device, comprising the steps of: providing a semiconductor substrate having a first major surface, and having a plurality of doped regions on a side adjacent to the first major surface; forming a first An oxide layer on the first main surface, wherein the first oxide layer has a thickness of less than 5 nm; forming a first metal pattern layer on the first oxide layer, the first metal pattern layer being projected to the first The pattern shape of the main surface is included in a region of the doped region, wherein the first metal pattern layer has a thickness between 15 nm and 20 nm; forming a second oxide layer covering the first oxide a layer and the first metal pattern layer, wherein the second oxide layer has a thickness of between 10 nm and 20 nm; and directly forming a pattern shape by using an electroplating process corresponding to one of the first metal pattern layers A metal pattern layer is on the second oxide layer. The manufacturing method of claim 1, wherein the semiconductor device is a photovoltaic semiconductor device, and the semiconductor substrate further has a second main surface opposite to the first main surface, wherein the manufacturing method further comprises forming An anti-reflective layer is on the second major surface. The manufacturing method of claim 1, wherein the forming of the first oxide layer further comprises removing a native oxide on the first major surface. The manufacturing method of claim 1, wherein the material of the first oxide layer is ceria, yttria, titania, zinc oxide, aluminum oxide or tin dioxide, and the material of the second oxide layer is two. Cerium oxide, cerium oxide, titanium dioxide, zinc oxide , alumina or tin dioxide. A semiconductor device comprising: a semiconductor substrate having a corresponding first main surface and a second main surface, the semiconductor substrate having a plurality of doped regions on a side adjacent to the first main surface; a first oxidation a layer formed on the first main surface of the semiconductor substrate, wherein the first oxide layer has a thickness of less than 5 nm; a first metal pattern layer is formed on the first oxide layer, the first metal pattern layer The pattern shape projected onto the first main surface is included in a region of the doped region, wherein the first metal pattern layer has a thickness between 15 nm and 20 nm; and a second oxide layer, Covering the first oxide layer and the first metal pattern layer, wherein the second oxide layer has a thickness of between 10 nm and 20 nm; and a second metal pattern layer is formed on the second oxide layer, And the pattern shape of the second metal pattern layer corresponds to the pattern shape of the first metal pattern layer; and an anti-reflection layer is formed on the second main surface of the semiconductor substrate. The semiconductor device according to claim 5, wherein the material of the first oxide layer is ceria, yttria, titania, zinc oxide, aluminum oxide or tin dioxide, and the material of the second oxide layer is two Cerium oxide, cerium oxide, titanium dioxide, zinc oxide, aluminum oxide or tin dioxide.