Polysilicon Resistor Single Implant Mask Segmentation

Solution Overview

Problem

Traditional polysilicon resistor fabrication requires multiple mask and implant steps to achieve multiple resistance values, leading to reduced performance and manufacturing inefficiencies.

Innovation Solution

A mask with a set of openings is formed over the resistor surface in a predetermined pattern, allowing a single implant dose to create multiple regions with different resistance values, reducing the need for multiple masking and implantation steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple mask and implant steps are used to achieve multiple resistance values, then different resistance values can be obtained, but manufacturing complexity and process time increase

Engineering Contradiction:

Improvemultiple resistance valuesVSAvoidmask and implant steps

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The mask is segmented into multiple regions with different opening patterns, where each region corresponds to a specific resistance value. The mask includes a first region with first openings, a second region with second openings, and a third region with third openings, allowing simultaneous formation of multiple resistance values in a single implantation process.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple implantation steps are merged into a single implantation step by designing the mask with multiple regions that expose different areas of the polysilicon layer simultaneously. This combines what would traditionally require sequential processing into one unified operation, reducing manufacturing complexity.

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If multiple mask and implant steps are used to achieve multiple resistance values, then different resistance values can be obtained, but manufacturing efficiency decreases

Engineering Contradiction:

Improvemultiple resistance valuesVSAvoidmanufacturing efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The mask is segmented into multiple regions with different opening patterns, where each region corresponds to a specific resistance value. The mask includes a first region with first openings, a second region with second openings, and a third region with third openings, allowing simultaneous formation of multiple resistance values in a single implantation process.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple implantation steps are merged into a single implantation step by designing the mask with multiple regions that expose different areas of the polysilicon layer simultaneously. This combines what would traditionally require sequential processing into one unified operation, reducing manufacturing complexity.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If traditional implantation over entire resistor surface is used, then simple process is maintained, but resistor mismatch increases

Engineering Contradiction:

Improveimplantation processVSAvoidresistor mismatch

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

Different regions of the mask provide different local qualities of dopant exposure. The first region, second region, and third region have different opening patterns that create locally optimized dopant distribution, ensuring precise resistance control in each area while maintaining overall process simplicity.

Inventive Principle:

Principle #3Local quality

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 enables the formation of polysilicon resistors with multiple resistance values using a single implant dose, improving device performance and manufacturing efficiency by minimizing mask numbers and resistor mismatch.

Implementation Method 1

The resistor is then subjected to a single implant dose via the openings

Methodology Applied

Scientific EffectIon implantation: Ion Implantation

Data Source

PatentUS8946039B2Polysilicon resistor formation

Publication Date: 2015.02.03 GLOBALFOUNDRIES US INC

AI summary

Aspects of the present invention relate to an approach for implanting and forming a polysilicon resistor with a single implant dose. Specifically, a mask having a set of openings is formed over a resistor surface. The set of openings are typically formed in a column-row arrangement according to a predetermined pattern. Forming the mask in this manner allows the resistor surface to have multiple regions/zones. A first region is defined by the set of openings in the mask, and a second region is defined by the remaining portions of the mask. The resistor is then subjected to a single implant dose via the openings. Implanting the resistor in this manner allows the resistor to have multiple resistance values (i.e., a first resistance value in the first region, and a second resistance value in the second region).