Abstract: A method for fabricating electronic and photonic devices on a semiconductor substrate using complementary-metal oxide semiconductor (CMOS) technology is disclosed. A substrate is initially patterned to form a first region for accommodating electronic devices and a second region for accommodating photonic devices. The substrate within the first region is thicker than the substrate within the second region. Next, an oxide layer is formed on the substrate. The oxide layer within the first region is thinner than the oxide layer within the second region. A donor wafer is subsequently placed on top of the oxide layer. The donor substrate includes a bulk silicon substrate, a sacrificial layer and a silicon layer. Finally, the bulk silicon substrate and the sacrificial layer are removed from the silicon layer such that the silicon layer remains on the oxide layer.

Abstract: A method for growing germanium epitaxial films is disclosed. Initially, a silicon substrate is preconditioned with hydrogen gas. The temperature of the preconditioned silicon substrate is then decreased, and germane gas is flowed over the preconditioned silicon substrate to form an intrinsic germanium seed layer. Next, a mixture of germane and phosphine gases can be flowed over the intrinsic germanium seed layer to produce an n-doped germanium seed layer. Otherwise, a mixture of diborane and germane gases can be flowed over the intrinsic germanium seed laser to produce a p-doped germanium seed layer. At this point, a bulk germanium layer can be grown on top of the doped germanium seed layer.

Abstract: A method for growing germanium epitaxial films is disclosed. Initially, a silicon substrate is preconditioned with hydrogen gas. The temperature of the preconditioned silicon substrate is then decreased, and germane gas is flowed over the preconditioned silicon substrate to form an intrinsic germanium seed layer. Next, a mixture of germane and phosphine gases can be flowed over the intrinsic germanium seed layer to produce an n-doped germanium seed layer. Otherwise, a mixture of diborane and germane gases can be flowed over the intrinsic germanium seed layer to produce a p-doped germanium seed layer. At this point, a bulk germanium layer can be grown on top of the doped germanium seed layer.

Abstract: A method for fabricating butt-coupled electro-absorptive modulators is disclosed. A butt-coupled electro-absorptive modulator with minimal dislocations in the electro-absorptive material is produced by adding a dielectric spacer for lining the coupling region before epitaxially growing the SiGe or other electro-absorptive material. It has been determined that during the SiGe growth, the current process has exposed single crystal silicon at the bottom of the hole and exposed amorphous silicon on the sides. SiGe growth on the amorphous silicon is expected to have more dislocations than single crystal silicon. There should also be dislocations or fissures where the SiGe growth from the each nucleation source finally join. Thus, a dielectric sidewall can protect an exposed waveguide face from any etching from an aggressive surface preparation prior to epi growth.

Abstract: An asymmetric slotted waveguide and method for fabricating the same. The slotted waveguide is constructed in silicon-on-insulator using a Complementary metal-oxide-semiconductor (CMOS) process. One or more wafers can be coated with a photo resist material using a photolithographic process in order to thereby bake the wafers via a post apply bake (PAB) process. An anti-reflective coating (TARC) can be further applied on the wafers and the wafers can be exposed on a scanner for the illumination conditions. After a post exposure bake (PEB), the wafers can be developed in a developer using a puddle develop process. Finally, the printed wafers can be processed using a shrink process to reduce the critical dimension (CD) of the slot and thereby achieve an enhanced asymmetric slotted waveguide that is capable of guiding the optical radiation in a wide range of optical modulation applications using an electro-optic polymer cladding.

Abstract: A method for fabricating electronic and photonic devices on a semiconductor substrate using complementary-metal oxide semiconductor (CMOS) technology is disclosed. A substrate is initially patterned to form a first region for accommodating electronic devices and a second region for accommodating photonic devices. The substrate within the first region is thicker than the substrate within the second region. Next, an oxide layer is formed on the substrate. The oxide layer within the first region is thinner than the oxide layer within the second region. A donor wafer is subsequently placed on top of the oxide layer. The donor substrate includes a bulk silicon substrate, a sacrificial layer and a silicon layer. Finally, the bulk silicon substrate and the sacrificial layer are removed from the silicon layer such that the silicon layer remains on the oxide layer.

Abstract: A method for integrating a slotted waveguide into a CMOS process is disclosed. A slot can be patterned on a SOI wafer by etching a first pad hard mask deposited over the wafer. The slot is then filled with a nitride plug material by depositing a second pad hard mask over the first pad hard mask. A waveguide in association with one or more electronic and photonic devices can also be patterned on the SOI wafer. The trenches can be filled with an isolation material and then polished. Thereafter, the first and second pad hard masks can be stripped from the wafer. The slot can once again be filled with the nitride plug material and patterned. After forming one or more electronic and photonic devices on the wafer using a standard CMOS process, a via can be opened down to the nitride plug and the nitride plug can then be removed.

Abstract: An improved method for manufacturing a lateral germanium detector is disclosed. A detector window is opened through an oxide layer to expose a doped single crystalline silicon layer situated on a substrate. Next, a single crystal germanium layer is grown within the detector window, and an amorphous germanium layer is grown on the oxide layer. The amorphous germanium layer is then polished to leave only a small portion around the single crystal germanium layer. A dielectric layer is deposited on the amorphous germanium layer and the single crystal germanium layer. Using resist masks and ion implants, multiple doped regions are formed on the single crystal germanium layer. After opening several oxide windows on the dielectric layer, a refractory metal layer is deposited on the doped regions to form multiple germanide layers.

Abstract: An asymmetric slotted waveguide and method for fabricating the same. The slotted waveguide is constructed in silicon-on-insulator using a Complementary metal-oxide-semiconductor (CMOS) process. One or more wafers can be coated with a photo resist material using a photolithographic process in order to thereby bake the wafers via a post apply bake (PAB) process. An anti-reflective coating (TARC) can be further applied on the wafers and the wafers can be exposed on a scanner for the illumination conditions. After a post exposure bake (PEB), the wafers can be developed in a developer using a puddle develop process. Finally, the printed wafers can be processed using a shrink process to reduce the critical dimension (CD) of the slot and thereby achieve an enhanced asymmetric slotted waveguide that is capable of guiding the optical radiation in a wide range of optical modulation applications using an electro-optic polymer cladding.

Abstract: A method for integrating a slotted waveguide into a CMOS process is disclosed. A slot can be patterned on a SOI wafer by etching a first pad hard mask deposited over the wafer. The slot is then filled with a plug material by depositing a second pad hard mask over the first pad hard mask. A waveguide in association with one or more electronic and photonic devices can also be patterned on the SOI wafer. The trenches can be filled with an isolation material and then polished. Thereafter, the first and second pad hard masks can be stripped from the wafer. The slot can once again be filled with the plug material and patterned. After forming one or more electronic and photonic devices on the wafer using the standard CMOS process, a via can be opened up down to the nitride plug and the nitride plug can then be removed.

Abstract: A method for growing germanium epitaxial films is disclosed. Initially, a silicon substrate is preconditioned with hydrogen gas. The temperature of the preconditioned silicon substrate is then decreased, and germane gas is flowed over the preconditioned silicon substrate to form an intrinsic germanium seed layer. Next, a mixture of germane and phosphine gases can be flowed over the intrinsic germanium, seed layer to produce an n-doped germanium seed layer. Otherwise, a mixture of diborane and germane gases can be flowed over the intrinsic germanium seed layer to produce a p-doped germanium seed layer. At this point, a hulk germanium layer can be grown on top of the doped germanium seed layer.

Abstract: An improved method for manufacturing a lateral germanium detector is disclosed. A detector window is opened through an oxide layer to expose a doped single crystalline silicon layer situated on a substrate. Next, a single crystal germanium layer is grown within the detector window, and an amorphous germanium layer is grown on the oxide layer. The amorphous germanium layer is then polished to leave only a small portion around the single crystal germanium layer. A dielectric layer is deposited on the amorphous germanium layer and the single crystal germanium layer. Using resist masks and ion implants, multiple doped regions are formed on the single crystal germanium layer. After opening several oxide windows on the dielectric layer, a refractory metal layer is deposited on the doped regions to form multiple germanide layers.

Abstract: A method for manufacturing multiple layers of waveguides is disclosed. Initially, a first cladding layer is deposited on a substrate, a first inner cladding layer is then deposited on the first cladding layer, and a first waveguide material is deposited on the first inner cladding layer. The first inner cladding layer and the first waveguide material are then selectively etched to form a first waveguide layer. Next, a second inner cladding layer followed by a second cladding layer are deposited on the first waveguide layer. The second inner cladding layer and the second cladding layer are removed by using a chemical-mechanical polishing process selective to the first waveguide material. A third inner cladding layer followed by a second waveguide material are deposited on the first waveguide material. The third inner cladding layer and the second waveguide material are then selectively etched to form a second waveguide layer.

Abstract: Techniques are disclosed for efficiently fabricating semiconductors including waveguide structures. In particular, a two-step hardmask technology is provided that enables a stable etch base within semiconductor processing environments, such as the CMOS fabrication environment. The process is two-step in that there is deposition of a two-layer hardmask, followed by a first photolithographic pattern, followed by a first silicon etch, then a second photolithographic pattern, and then a second silicon etch. The process can be used, for example, to form a waveguide structure having both ridge and channel configurations, or a waveguide (ridge and/or channel) and a salicide heater structure, all achieved using the same hardmask. The second photolithographic pattern allows for the formation of the lower electrical contacts to the waveguides (or other structures) without a complicated rework of the hardmask.

Abstract: A method for fabricating selectively coupled optical waveguides on a substrate is disclosed. Initially, a first layer of waveguide material is deposited on a substrate. The first layer of waveguide material is then etched to form multiple level one waveguides and fill shapes. A dielectric layer is deposited on top of the level one waveguides and fill shapes. The surface profile of the dielectric layer deposition tracks the pattern density of the fill shapes. After the surface of the dielectric layer has been polished, a second layer of waveguide material is deposited on the substrate. At least one optically coupled waveguide structure, which is formed by a first level one waveguide and a first level two waveguide, is located adjacent to at least one non-optically coupled waveguide structure, which is formed by a second level one waveguide and a second level two waveguide.

Abstract: Techniques are disclosed that facilitate fabrication of semiconductors including structures and devices of varying thickness. One embodiment provides a method for semiconductor device fabrication that includes thinning a region of a semiconductor wafer upon which the device is to be formed thereby defining a thin region and a thick region of the wafer. The method continues with forming on the thick region one or more photonic devices and/or partially depleted electronic devices, and forming on the thin region one or more fully depleted electronic devices. Another embodiment provides a semiconductor device that includes a semiconductor wafer defining a thin region and a thick region. The device further includes one or more photonic devices and/or partially depleted electronic devices formed on the thick region, and one or more fully depleted electronic devices formed on the thin region. An isolation area can be formed between the thin region and the thick region.

Abstract: A method for growing germanium epitaxial films is disclosed. Initially, a silicon substrate is preconditioned with hydrogen gas. The temperature of the preconditioned silicon substrate is then decreased, and germane gas is flowed over the preconditioned silicon substrate to form an intrinsic germanium seed layer. Next, a mixture of germane and phosphine gases can be flowed over the intrinsic germanium seed layer to produce an n-doped germanium seed layer. Otherwise, a mixture of diborane and germane gases can be flowed over the intrinsic germanium seed layer to produce a p-doped germanium seed layer. At this point, a bulk germanium layer can be grown on top of the doped germanium seed layer.

Abstract: Techniques are disclosed that facilitate fabrication of semiconductors including structures and devices of varying thickness. One embodiment provides a method for semiconductor device fabrication that includes thinning a region of a semiconductor wafer upon which the device is to be formed thereby defining a thin region and a thick region of the wafer. The method continues with forming on the thick region one or more photonic devices and/or partially depleted electronic devices, and forming on the thin region one or more fully depleted electronic devices. Another embodiment provides a semiconductor device that includes a semiconductor wafer defining a thin region and a thick region. The device further includes one or more photonic devices and/or partially depleted electronic devices formed on the thick region, and one or more fully depleted electronic devices formed on the thin region. An isolation area can be formed between the thin region and the thick region.

Abstract: A method for fabricating butt-coupled electro-absorptive modulators is disclosed. A butt-coupled electro-absorptive modulator with minimal dislocations in the electro-absorptive material is produced by adding a dielectric spacer for lining the coupling region before epitaxially growing the SiGe or other electro-absorptive material. It has been determined that during the SiGe growth, the current process has exposed single crystal silicon at the bottom of the hole and exposed amorphous silicon on the sides. SiGe growth on the amorphous silicon is expected to have more dislocations than single crystal silicon. There should also be dislocations or fissures where the SiGe growth from the each nucleation source finally join. Thus, a dielectric sidewall can protect an exposed waveguide face from any etching from an aggressive surface preparation prior to epi growth.

Abstract: Techniques are disclosed that facilitate fabrication of semiconductors including structures and devices of varying thickness. One embodiment provides a method for semiconductor device fabrication that includes thinning a region of a semiconductor wafer upon which the device is to be formed thereby defining a thin region and a thick region of the wafer. The method continues with forming on the thick region one or more photonic devices and/or partially depleted electronic devices, and forming on the thin region one or more fully depleted electronic devices. Another embodiment provides a semiconductor device that includes a semiconductor wafer defining a thin region and a thick region. The device further includes one or more photonic devices and/or partially depleted electronic devices formed on the thick region, and one or more fully depleted electronic devices formed on the thin region. An isolation area can be formed between the thin region and the thick region.