Semiconductor substrate and method of manufacturing the same
First Claim
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1. A method of manufacturing a semiconductor substrate comprising the steps of:
- preparing a first substrate having a porous region including at least two layers different in porosity and a non-porous layer formed on said porous region;
bonding a surface of said non-porous layer of said first substrate to a surface of a second substrate;
separating said first and second substrates from each other to transfer said non-porous layer to said second substrate; and
removing the residual portion of the porous region remaining on a separation surface of said second substrate or making the residual portion non-porous to smooth said separation surface;
wherein the step of preparing said first substrate comprises a step of forming a first porous layer of 1 μ
m or less thickness, a second porous layer adjacent to said first porous layer and high in porosity, and said non-porous layer adjacent to said first porous layer.
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Abstract
A manufacturing method excellent in controllability, productivity and economics of a high-quality SOI wafer and a wafer manufactured by that method are provided. After wafer bonding, separation is made on an interface of a high porosity layer in a porous region including a low porosity layer and the high porosity layer in a surface formed on a main surface side of a first Si substrate 2 to transfer a non-porous layer onto a second substrate. After separation at the high porosity layer, a residual low porosity thin layer is made non-porous by a smoothing process such as hydrogen annealing without using selective etching.
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Citations
82 Claims
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1. A method of manufacturing a semiconductor substrate comprising the steps of:
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preparing a first substrate having a porous region including at least two layers different in porosity and a non-porous layer formed on said porous region; bonding a surface of said non-porous layer of said first substrate to a surface of a second substrate; separating said first and second substrates from each other to transfer said non-porous layer to said second substrate; and removing the residual portion of the porous region remaining on a separation surface of said second substrate or making the residual portion non-porous to smooth said separation surface; wherein the step of preparing said first substrate comprises a step of forming a first porous layer of 1 μ
m or less thickness, a second porous layer adjacent to said first porous layer and high in porosity, and said non-porous layer adjacent to said first porous layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
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41. A method of manufacturing a semiconductor article comprising the steps of:
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preparing a first substrate having a porous region including at least two layers different in porosity and a non-porous layer formed on said porous region; bonding a surface of said non-porous layer of said first substrate to a surface of a second substrate; and separating said first and second substrates from each other to transfer said non-porous layer to said second substrate; wherein the step of preparing said first substrate comprises a step of forming a first porous layer of 1 μ
m or less thickness, a second porous layer adjacent to said first porous layer and high in porosity, and said non-porous layer adjacent to said first porous layer. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 72, 73, 74, 75, 76, 77, 78, 79, 80)
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71. A method of manufacturing a semiconductor article as claimed in clam 41, wherein said second substrate is formed on an Si substrate, and an insulating film is formed on at least one of the surfaces to be bonded.
- 81. A method of manufacturing a semiconductor article as claimed in clam 41, further comprising a step of smoothing a separation surface of the second substrate.
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