GaInAsP Polishing Agent Chemical Balance for Surface Quality
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Solution Overview
Problem
Existing polishing methods for GaInAsP compound semiconductors face challenges in controlling the chemical action of polishing agents, leading to surface micro-roughness, light point defects, and reduced polishing rates, making it difficult to maintain surface quality while achieving high polishing efficiency.
Innovation Solution
A polishing agent comprising an alkali metal carbonate, an organic salt of an alkali metal, a chlorine-based oxidizer, and a phosphate, with specific concentration ranges and pH control, is used to balance chemical and mechanical actions, minimizing haze and LPDs while maintaining high polishing rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the oxidizing power of the polishing agent is increased, then the polishing rate is improved, but surface micro-roughness (haze) increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the concentrations of multiple chemical components in the polishing agent. Specifically, it adjusts the oxidizing agent concentration to 0.01-0.05 mol/L and the alkaline earth metal carbonate concentration to 0.02-0.08 mol/L, along with other components, to achieve an optimal balance between polishing rate and surface quality. This systematic parameter optimization resolves the contradiction by finding the precise concentration range where both high polishing rate and low haze are achieved simultaneously.
2Productivity
If the alkalinity of the polishing agent is increased, then the polishing rate is improved, but light point defects (LPDs) in the substrate face increase
Solution Approach 1:
The patent resolves this contradiction through parameter changes by controlling the alkalinity within a specific range. It sets the alkaline earth metal carbonate concentration to 0.02-0.08 mol/L and adjusts the pH to 8.5-9.5, while also controlling the oxidizing agent concentration to 0.01-0.05 mol/L. This balanced parameter control ensures sufficient chemical action for high polishing rate while preventing excessive alkalinity that would cause light point defects.
3Manufacturing precision
If the chemical action of the polishing agent is weakened, then surface quality is improved, but the polishing rate drops
Solution Approach 1:
The patent applies the composite materials principle by formulating a polishing agent with multiple synergistic components. It combines oxidizing agents (sodium dichloroisocyanurate, calcium hypochlorite), alkaline earth metal carbonates (calcium carbonate, strontium carbonate), phosphates, and organic salts in specific concentrations. This composite formulation creates a balanced chemical system where the interactions between components provide both sufficient chemical action for high polishing rate and controlled surface quality, resolving the contradiction between surface quality and polishing rate.
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
The proposed solution effectively reduces surface defects and maintains high polishing rates, ensuring favorable surface quality and efficient polishing of GaInAsP compound semiconductor substrates.
Implementation Method 1
The polishing methods employing the polishing agents of the abovementioned Patent References 1 through 4 adopt a chemical polishing process that while oxidizing the substrate face at the same time removes the oxidation layer.
Data Source
AI summary
Afforded are a polishing agent, and a compound semiconductor manufacturing method and semiconductor device manufacturing method utilizing the agent, whereby the surface quality of compound semiconductor substrates can be favorably maintained, and high polishing rates can be sustained as well. The polishing agent is a polishing agent for GaαIn(1-α)AsβP(1-β) (0≦α≦1; 0≦β≦1) compound semiconductors, and includes an alkali metal carbonate, an alkali metal organic salt, a chlorine-based oxidizer, and an alkali metal phosphate, wherein the sum of the concentrations of the alkali metal carbonate and the alkali metal organic salt is between 0.01 mol/L and 0.02 mol/L, inclusive. The compound semiconductor manufacturing method comprises a step of preparing a GaαIn(1-α)AsβP(1-β) (0≦α≦1; 0≦β≦1) compound semiconductor, and a step of polishing the face of the compound semiconductor utilizing an aforedescribed polishing agent.