公开(公告)号：US12203191B2

公开(公告)日：2025-01-21

申请号：US18073228

申请日：2022-12-01

Applicant: BAE SYSTEMS Information and Electronic Systems Integration Inc.

Inventor： Peter G. Schunemann ,  Kevin T. Zawilski

IPC: C30B33/06 ,  C30B25/18 ,  C30B29/42 ,  C30B29/44 ,  C30B31/06

Abstract: A method of growing large GaAs or GaP IR window slabs by HVPE, and in embodiments by LP-HVPE, includes obtaining a plurality of thin, single crystal, epitaxial-quality GaAs or GaP wafers, cleaving the wafers into tiles having ultra-flat, atomically smooth, substantially perpendicular edges, and then butting the tiles together to form an HVPE substrate larger than 4 inches for GaP, and larger than 8 inches or even 12 inches for GaAs. Subsequent HVPE growth causes the individual tiles to fuse by optical bonding into a large “tiled” single crystal wafer, while any defects nucleated at the tile boundaries are healed, causing the tiles to merge with themselves and with the slab with no physical boundaries, and no degradation in optical quality. A dopant such as Si can be added to the epitaxial gases during the final HVPE growth stage to produce EMI shielded GaAs windows.

公开(公告)号：US12084791B2

公开(公告)日：2024-09-10

申请号：US18073183

申请日：2022-12-01

Applicant: BAE SYSTEMS Information and Electronic Systems Integration Inc.

Inventor： Peter G. Schunemann ,  Kevin T. Zawilski

IPC: C30B29/42 ,  C23C16/30 ,  C30B29/44 ,  C30B33/06

CPC classification number: C30B33/06 ,  C23C16/30 ,  C30B29/42 ,  C30B29/44 ,  Y10T428/162

Abstract: A method of making GaP window slabs having largest dimensions of greater than 4 inches and GaAs IR window slabs having largest dimensions of greater than 8 inches, includes slicing and dicing at least one smaller GaAs or GaP single crystal boule, which can be a commercial boule, to form a plurality of rectangular slabs. The slabs are ground to have precisely perpendicular edges, which are polished to be ultra-flat and ultra-smooth, for example to a flatness of at least λ/10, and a roughness Ra of less than 10 nanometers. The slab edges are then aligned and fused via optical-contacting/bonding to create a large GaAs or GaP slab having negligible bond interface losses. A conductive, doped GaAs or GaP layer can be applied to the window for EMI shielding in a subsequent vacuum deposition step, followed by applying anti-reflection (AR) coatings to one or both of the slab faces.

公开(公告)号：US20240188261A1

公开(公告)日：2024-06-06

申请号：US18073179

申请日：2022-12-01

Applicant: BAE SYSTEMS Information and Electronic Systems Integration Inc.

Inventor： Peter G. Schunemann ,  Kevin T. Zawilski

IPC: H05K9/00 ,  C09D5/00 ,  C23C16/30 ,  C23C16/52 ,  C30B17/00 ,  C30B29/42 ,  C30B29/60 ,  C30B35/00

CPC classification number: H05K9/0005 ,  C09D5/006 ,  C23C16/306 ,  C23C16/52 ,  C30B17/00 ,  C30B29/42 ,  C30B29/602 ,  C30B35/002

Abstract: GaAs IR window slabs having largest dimensions that are greater than 8 inches, and preferably greater than 12 inches, are grown using the Horizontal Gradient Freeze (HGF) method. Heat extraction is simplified by using a shallow horizontal boat that is only slightly deeper than the desired window thickness, thereby enabling growth of large slabs while also minimizing material waste and fabrication cost as compared to slicing and shaping thick plates from large, melt-grown boules. Single crystal seeds can be used to optimize the final orientation of the slabs and minimize secondary nucleation, thereby maximizing yield. A conductive doped GaAs layer can be applied to the IR window slab to provide EMI shielding. The temperature gradient during HGF can be between 1° C./cm and 3° C./cm, and the directional solidification can be at a rate of between 0.25 mm/h and 2.5 mm/h.

公开(公告)号：US20240184015A1

公开(公告)日：2024-06-06

申请号：US18073177

申请日：2022-12-01

Applicant: BAE SYSTEMS Information and Electronic Systems Integration Inc.

Inventor： Peter G. Schunemann ,  Kevin T. Zawilski

IPC: G02B1/02 ,  C30B25/18 ,  C30B29/42 ,  C30B29/44 ,  C30B31/06 ,  H05K9/00

CPC classification number: G02B1/02 ,  C30B25/18 ,  C30B29/42 ,  C30B29/44 ,  C30B31/06 ,  H05K9/0081 ,  H05K9/0094

Abstract: IR window slabs of GaP greater than 4 inches diameter, and of GaAs greater than 8 inches diameter, are grown on a substrate using Hydride Vapor Phase Epitaxy (HVPE), preferably low pressure HVPE (LP-HVPE). Growth rates can be hundreds of microns per hour, comparable to vertical melt growth. GaAs IR windows produced by the disclosed method exhibit lower absorption than crystals grown from vertical melt near 1 micron, due to reduced impurities and reduced growth temperatures that limit the solubility of excess arsenic, and thereby reduce the “EL2” defects that cause high absorption near one micron in conventional GaAs boules. Silicon wafers can be used as HVPE substrates. For GaAs, layers of GaAsP that vary from 0% to 100% As can be applied to the substrate. EMI shielding can be applied by adding a dopant during the final stage of growth to provide a conductive GaAs or GaP layer.

公开(公告)号：US20240183065A1

公开(公告)日：2024-06-06

申请号：US18073228

申请日：2022-12-01

Applicant: BAE SYSTEMS Information and Electronic Systems Integration Inc.

Inventor： Peter G. Schunemann ,  Kevin T. Zawilski

IPC: C30B25/18 ,  C30B29/42 ,  C30B29/44 ,  C30B31/06 ,  C30B33/06

CPC classification number: C30B25/186 ,  C30B29/42 ,  C30B29/44 ,  C30B31/06 ,  C30B33/06

Abstract: A method of growing large GaAs or GaP IR window slabs by HVPE, and in embodiments by LP-HVPE, includes obtaining a plurality of thin, single crystal, epitaxial-quality GaAs or GaP wafers, cleaving the wafers into tiles having ultra-flat, atomically smooth, substantially perpendicular edges, and then butting the tiles together to form an HVPE substrate larger than 4 inches for GaP, and larger than 8 inches or even 12 inches for GaAs. Subsequent HVPE growth causes the individual tiles to fuse by optical bonding into a large “tiled” single crystal wafer, while any defects nucleated at the tile boundaries are healed, causing the tiles to merge with themselves and with the slab with no physical boundaries, and no degradation in optical quality. A dopant such as Si can be added to the epitaxial gases during the final HVPE growth stage to produce EMI shielded GaAs windows.

公开(公告)号：US20150235848A1

公开(公告)日：2015-08-20

申请号：US14422850

申请日：2014-06-11

Applicant: BAE Systems Information and Electronic Systems Integration Inc.

Inventor： Peter G. Schunemann ,  Kevin T. Zawilski

IPC: H01L21/02 ,  C22C28/00

CPC classification number: H01L21/02546 ,  C22C28/00 ,  C30B25/00 ,  C30B29/42 ,  H01L21/02395 ,  H01L21/0262

Abstract: A novel bulk GaAs with an increased carrier lifetime of at least 10 microseconds has been produced. This novel GaAs has many uses to improve optical and electrical devices. The method of producing the GaAs crystal involves using a technique called low pressure hydride phase epitaxy (LP-HVPE). In this technique, a gas containing Ga (typically GaCl) is reacted with a gas containing As (typically AsH3) at the surface of a GaAs substrate. When grown under the proper conditions, the epitaxial, vapor grown GaAs crystal has ultra-long free carrier lifetimes of at least one order of magnitude greater than that of the previous art of 1 microsecond. This very long free carrier lifetime GaAs will be particularly useful as a semiconductor radiation detector material and is also expected to be useful for many other applications than include medical imaging, solar cells, diode lasers, and optical limiters and other applications.

Abstract translation: 已经产生了具有至少10微秒的载流子寿命增加的新型体GaAs。 这种新型GaAs具有改进光电器件的许多用途。 制造GaAs晶体的方法涉及使用称为低压氢化物相外延（LP-HVPE）的技术。 在该技术中，含有Ga（通常为GaCl）的气体与在GaAs衬底的表面上含有As（通常为AsH 3）的气体反应）。 当在合适的条件下生长时，外延，气相生长的GaAs晶体的超长自由载流子寿命至少比先前技术的1微秒大一个数量级。 这种非常长的自由载流子寿命的GaAs将作为半导体辐射检测器材料是特别有用的，并且预期对于许多其它应用来说是有用的，包括医学成像，太阳能电池，二极管激光器和光学限制器以及其他应用。