Fin Structure Sidewall Angle Control for Ion Implantation Defect Prevention
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Solution Overview
Problem
Fin structures in semiconductor devices suffer from defects due to ion implantation damage, particularly because recrystallization after ion implantation proceeds only from the bottom, leading to incomplete recovery and residual defects, which are exacerbated by the small implanted area and slanted implantation direction.
Innovation Solution
The method involves forming Fin structures without an end face of the {111} plane on the sidewall and setting the sidewall angle to be smaller than the angle between the {111} plane and the bottom, typically less than 54.7°, to prevent defects caused by residual damage after ion implantation, and performing recovery heat treatment in a temperature range of 550° C. to 650° C. to evaluate and recrystallize the silicon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If ion implantation is performed on Fin structure, then doping can be achieved, but damage to silicon and defects occur due to accelerated ion impact
Solution Approach 1:
The patent applies parameter changes by controlling the crystal orientation of the silicon substrate (using <110> orientation instead of conventional <100>), adjusting the Fin structure geometry (sidewall angle less than 54.7°), and optimizing annealing temperature (550-650°C) to achieve complete recrystallization and eliminate ion implantation damage while maintaining doping effectiveness
2Reliability
If Fin structure is used to achieve high performance, then device performance improves, but defects occur because recrystallization proceeds only from bottom after ion implantation
Solution Approach 1:
The patent changes the crystal orientation parameter to <110> and controls the sidewall angle to be less than 54.7°, which enables the {111} plane to be exposed on the sidewall. This geometric parameter change allows recrystallization to proceed from both bottom and sidewall during annealing, completely eliminating ion implantation defects while maintaining Fin structure performance
Solution Approach 2:
The patent transitions from conventional <100> orientation to <110> orientation, which changes the crystal plane exposure from horizontal only to including vertical sidewall exposure. This dimensional change in crystal orientation enables dual-directional recrystallization (bottom and sidewall), solving the incomplete recovery problem
3Object-affected harmful factors
If wafer rotation is performed to prevent defects, then defect occurrence decreases, but mobility of electrons and holes is sacrificed
Solution Approach 1:
The patent changes the crystal orientation parameter from <100> to <110> and optimizes the sidewall angle, which inherently prevents defect formation through proper crystal plane exposure during annealing. This parameter change eliminates the need for wafer rotation, thereby maintaining optimal carrier mobility while preventing defects
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces defects in Fin structures by preventing crystal growth along the {111} plane, allowing for accurate evaluation of the ion implantation defect recovery process and ensuring complete recrystallization without residual damage.
Implementation Method 1
The ion implantation technology is a very important method for manufacturing semiconductor parts, including various transistors. In this method, however, an implantation element to be a dopant is ionized and accelerated, and then implanted into silicon.
Implementation Method 2
based on a method of heat treatment at a high temperature that is sufficient to reconstruct damaged bond of the silicon (e.g., silicon changed to amorphous) to perform single-crystallization, thereby recovering the same
Implementation Method 3
recrystallization after ion implantation proceeds from only the bottom of the Fin structure
Data Source
AI summary
A method for manufacturing a semiconductor device, including forming a Fin structure on a semiconductor silicon substrate, performing ion implantation into the Fin structure, and subsequently performing recovery heat treatment on the semiconductor silicon substrate to recrystallize silicon of the Fin structure, wherein the Fin structure is processed so as not to have an end face of a {111} plane of the semiconductor silicon onto a sidewall of the Fin structure to be formed. It also includes a method for manufacturing a semiconductor device that is capable of preventing a defect from being introduced into a Fin structure when the Fin structure is subjected to ion implantation and recovery heat treatment.