Semiconductor Doping via Passivation Layer Diffusion
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Solution Overview
Problem
Current methods for producing doped regions in semiconductor layers are costly and inefficient, particularly in photovoltaic solar cells, as they require complex and expensive processes for doping and subsequent removal of doped silicate glass, and do not effectively reduce surface recombination speeds for minority charge carriers.
Innovation Solution
A method involving the application of a passivation layer followed by a doping layer, where the dopant diffuses through the passivation layer into the semiconductor layer, eliminating the need for post-diffusion removal of the doping layer and enabling simultaneous surface passivation, using chemical and/or physical deposition processes like CVD or PVD.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a doped silicate glass layer is applied for doping, then doping can be achieved, but the layer must be removed afterward due to hygroscopic properties causing surface defects
Solution Approach 1:
The harmful silicate glass layer is completely removed by etching after doping, extracting only the beneficial dopant diffusion while eliminating the source of surface defects and hygroscopic problems
Solution Approach 2:
A native oxide layer is formed as an intermediary between the silicate glass and the semiconductor surface during doping, preventing direct contact and reducing the harmful effects of the silicate glass while allowing dopant diffusion to proceed
2Manufacturing precision
If multiple process steps including vacuum deposition are used for doping and passivation, then high-quality doping can be achieved, but process complexity and cost increase
Solution Approach 1:
The doping layer and passivation layer are deposited in a single continuous process without breaking vacuum, merging two critical steps into one operation and eliminating the need for intermediate vacuum breaking and re-establishment
Solution Approach 2:
The same vacuum deposition process is used to deposit both the doping layer and the passivation layer, making the deposition system multi-functional and eliminating the need for separate processing equipment or steps
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method reduces the complexity and cost of producing doped regions while maintaining effective surface passivation, allowing for high-quality doping and passivation without additional vacuum steps, thus enhancing the efficiency and cost-effectiveness of semiconductor layer processing.
Implementation Method 1
the dopant is diffused into the semiconductor layer by the action of heat
Implementation Method 2
surface passivation in a cost-effective manner in the sense of reducing the surface recombination speed for minority charge carriers of the semiconductor layer
Implementation Method 3
using chemical and/or physical deposition processes like CVD or PVD
Implementation Method 4
using chemical and/or physical deposition processes like CVD or PVD
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
The invention relates to a method for producing a doped region in a semiconductor layer, having a method step A, in which a doping layer is applied onto the semiconductor layer, said doping layer containing at least one dopant for producing the doped region, and a method step B, in which the dopant is diffused into the semiconductor layer under the effect of heat. The invention is characterized in that a passivating layer is directly or indirectly applied onto a surface of the semiconductor layer prior to method step A in a method step A0, the doping layer is directly or indirectly applied onto the passivating layer in method step A, and the dopant is introduced from the doping layer into the semiconductor layer through the passivating layer in method step B, wherein the passivating layer (4) is applied by means of a chemical and/or physical method; the dopant is a dopant of the group consisting of boron, phosphorus, gallium, arsenic, or indium; the passivating layer (4) is formed with a dopant concentration less than 5x1019 cm-3 in method step A0; and the doping layer is formed with a dopant concentration greater than 1020 cm-3 in method step A.