Patent EP0257917A2 successfully refreshed from Google Patents.
← Back to Patent Explorer
EP0257917A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Method of producing soi devices

Assignee: AT&T Inc
•
Filing: 1987-08-12
•
Granted: —
•
Expires: 2007-08-12
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Disclosed are methods that result in substantial improvement of s ilicon- o n- i nsultator (SOI) device manufacture. We have discovered that carbon can be advantageously used as a wetting agent in the m elting- r ecrystallization (MR) method of producing SOI wafers. We have also found that contacting the wafer (typically subsequent to the formation thereon of a poly-Si layer on a SiO₂ layer but prior to the completion of formation of a SiO₂ cap layer on the poly-Si layer) with an atmosphere that comprises a wetting agent-containing molecular species (e.g., CH₄, NH₃), with the wafer at an appropriate elevated (e.g., 500-900°C) temperature, can reliably result in recrystallized Si films of high quality. Furthermore, we have discovered the existence of a previously unknown parameter regime (low thermal gradient across the resolidification front, typically no more than about 4°C/mm) for the MR process that can result in a highly perfect (χ min of 3%, subboundary spacing of about 50 µm, misalignment across subboundaries of the order of 0.1°) resolidified Si layer. Devices can be fabricated directly in this layer, or the layer can be used as seed substrate for the growth of a "thick" epitaxial Si layer of the type useful for the fabrication of high voltage semiconductor devices.

Inventors

  • 👤 Arthur Curtis Adams
  • 👤 Loren Neil Pfeiffer
  • 👤 Kenneth William West

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 04:22
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/24; C; C30; C30B; C30B13/00; C30B29/00; C30B29/02; C30B29/06; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/32; H10P14/3202; H10P14/3238; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3451; H10P14/3452; H10P14/3458; H10P14/3466; H10P14/38; H10P14/3802; H10P14/3806; H10P95/00; H10P95/90

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 183 words
A method of manufacturing an electronic device, comprising forming a multilayer structure on a single crystal Si substrate having a major surface by a process comprising forming a first SiO ₂ layer on the major surface of the Si substrate; forming a Si layer on the first SiO ₂ layer; forming a SiO ₂ cap layer on the Si layer; melting at least a portion of the Si layer and permitting resolidification of the portion of the Si melted layer, the resolidified Si layer being substantially monocrystalline; and forming the semiconductor device in the resolidified Si layer; CHARACTERIZED BY introducing into the multilayer structure an amount of wetting agent that is effective to cause substantial wetting of at least one of the first Sio ₂ layer and the SiO ₂ cap layer by the molten Si, said introducing being by a procedure that comprises contacting, prior to the completion of SiO ₂ cap forming step, the multilayer structure with an atmosphere that comprises a wetting-agent-containing molecular species while the multilayer structure is at a temperature that causes pyrolysis of the wetting-agent-containing molecular species.
Claim 2
Independent Claim 183 words
A method of manufacturing an electronic device, comprising forming a multilayer structure on a single crystal Si substrate having a major surface by a process comprising forming a first SiO ₂ layer on the major surface of the Si substrate; forming a Si layer on the first SiO ₂ layer; forming a SiO ₂ cap layer on the Si layer; melting at least a portion of the Si layer and permitting resolidification of the portion of the Si melted layer, the resolidified Si layer being substantially monocrystalline; and forming the semiconductor device in the resolidified Si layer; CHARACTERIZED BY introducing into the multilayer structure an amount of wetting agent that is effective to cause substantial wetting of at least one of the first Sio ₂ layer and the SiO ₂ cap layer by the molten Si, said introducing being by a procedure that comprises contacting, prior to the completion of SiO ₂ cap forming step, the multilayer structure with an atmosphere that comprises a wetting-agent-containing molecular species while the multilayer structure is at a temperature that causes pyrolysis of the wetting-agent-containing molecular species.
Claim 3
Dependent Claim 18 words
The method according to claim 1, CHARACTERIZED BY choosing the wetting agent from carbon, nitrogen and mixtures thereof.
Claim 4
Dependent Claim 35 words
The method according to claim 2, CHARACTERIZED BY choosing the wetting agent-containing molecular species from at least one of CH ₄, C ₂ H ₂, C ₂ H ₄, C ₂ H ₆, and NH₃.
Claim 5
Dependent Claim 30 words
The method according to claim 1 or 2, CHARACTERIZED IN THAT said contacting of the surface of the Si layer is with the atmosphere that comprises the wetting agent-containing molecular-species.
Claim 6
Dependent Claim 35 words
The method according to claim 1 or 2, CHARACTERIZED BY causing the atmosphere to contact the multilayer structure during formation of the SiO ₂ cap layer, with the atmosphere further comprising a Si-­containing molecular species.
Claim 7
Dependent Claim 63 words
The method according to claim 1, CHARACTERIZED BY causing the melted portion to move across at least a part of the Si layer associated with the melted portion being a resolidification front and a thermal gradient across the resolidification front at right angle thereto and in the plane of the Si film, with the thermal gradient being at most 4 ° C /mm.
Claim 8
Dependent Claim 62 words
The method according to claim 6, CHARACTERIZED BY substantially uniformly heating the Si substrate to a base temperature in the range from about 25 ° C -100 ° C below the melting temperature of Si, and providing additional heating means for non-uniformly heating the Si substrate and the multilayer structure thereon such that the melted portion of the Si layer is strip-like.
Claim 9
Dependent Claim 42 words
Method according to claim 6, CHARACTERIZED BY providing seeding means for contacting the single crystal Si substrate material with the molten Si such that the crystal orientation of the resolidified Si layer is determined by the crystal orientation of the Si substrate.
Claim 10
Dependent Claim 60 words
Method according to claim 1 or 6, CHARACTERIZED BY removing the SiO ₂ cap layer from at least part of the resolidified Si layer, and depositing Si onto the resolidified Si layer such that the deposited Si is epitaxial with the resolidified Si layer, forming a "thick" Si layer, with the semiconductor device being formed in the thick Si layer.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Maintenance schedule is calculated for granted US utility patents.

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag