Method for surface preparation Si(100) substrates

Simple SummaryContent extracted from patent full text and abstract with AI.

This patent describes a method for preparing contamination-free and smooth silicon (Si(100)) substrates with controlled surface structures (terraces) in a hydrogen atmosphere. By precisely adjusting the temperature, pressure, and cooling or heating rates depending on the crystal orientation of the substrate, the type and proportion of two terrace types—Type-A (dimers perpendicular to step edges) and Type-B (dimers parallel)—can be reproducibly controlled. This results in predictable surface morphologies, which are critical for the subsequent growth of high-quality semiconductor layers.

Use CasesContent extracted from patent full text and abstract with AI.

• Preparation of silicon substrates for advanced microelectronics and integrated circuit fabrication.
• Substrate engineering for high-efficiency photovoltaic cells, such as solar cells.
• Surface preparation before the epitaxial growth of III-V and other semiconductor layers on silicon.
• Manufacturing substrates for optoelectronic devices, including LEDs and lasers.
• Producing reference-grade silicon wafers for research and quality assessment in semiconductor processing laboratories.
• Enabling controlled domain structures for experimental studies in crystal growth and surface physics.

BenefitsContent extracted from patent full text and abstract with AI.

• Precise and reproducible control over surface domain structure of Si(100) substrates.
• Ability to select or mix terrace types, which improves compatibility with subsequent heteroepitaxial growth and reduces crystal defects (like antiphase domains).
• The process operates at moderate pressures, making it suitable and scalable for industrial applications without requiring ultra-high vacuum equipment.
• Enables formation of previously difficult-to-achieve surface types, such as Type-A terraces (DA-steps), as well as the more conventional Type-B (DB-steps).
• Supports in-situ monitoring via optical measurement techniques (RAS), ensuring process reliability and quality.
• Improves substrate surface quality, potentially enhancing device performance and yield in semiconductor manufacturing.

Technical Classifications (CPCs)

Inventors & Applicants

Patent Abstract

Surface preparation of contamination-free and smooth silicon(100) substrates with known disorientation in hydrogen environment at a process pressure, with a controllability of the formation of terraces of type-A for double stages with silicon dimers arranged perpendicular to the step edges, or type-B for double stages with silicon dimers arranged parallel to the steps edges, comprises adjusting the formation of type-A or type-B terraces with variable proportions and reducing the process temperature with a change rate of = 0.2?pC/second at a constant process pressure. Surface preparation of contamination-free and smooth silicon(100) substrates with known disorientation in hydrogen environment at a process pressure, with a controllability of the formation of terraces of type-A for double stages with silicon dimers arranged perpendicular to the step edges or type-B for double stages with silicon dimers arranged parallel to the steps edges, during the surface preparation of the hydrogen-terminated silicon(100) surface, at least by reducing the process temperature, comprises adjusting the formation of type-A or type-B terraces with variable proportions and reducing the process temperature with a change rate of = 0.2?pC/second at a constant process pressure according to: figure 2 (as given in the specification) with an average misorientation of the surface of the silicon(100) substrate at 0.5[deg] -4[deg] ; or figure 7 (as given in the specification) at a strong misorientation of the surface of the silicon(100) substrate, which is greater than 4[deg] , where the process temperature can be reduced to a rate of change of >= 2[deg] C/second, and the process pressure has rate of change of = 3 mbar/second according figure 12 (as given in the specification) with a small misorientation of the surface of the silicon(100) substrate of less than 0.5[deg] .