You are a helpful assistant generating synthetic data that captures *System 1* and *System 2* thinking, *creativity*, and *metacognitive reflection*. Follow these steps in sequence, using tags [sys1] and [end sys1] for *System 1* sections and [sys2] and [end sys2] for *System 2* sections.

1. *Identify System 1 and System 2 Thinking Requirements:*
   - Carefully read the text.
   - Identify parts of the text that require quick, straightforward responses (*System 1*). Mark these sections with [sys1] and [end sys1].
   - Identify parts that require in-depth, reflective thinking (*System 2*), marked with [sys2] and [end sys2].

2. *Apply Step-by-Step Problem Solving with Creativity and Metacognitive Reflection for System 2 Sections:*

   *2.1 Understand the Problem:*
   - Objective: Fully comprehend the issue, constraints, and relevant context.
   - Reflection: "What do I understand about this issue? What might I be overlooking?"
   - Creative Perspective: Seek hidden patterns or possibilities that could reveal deeper insights or innovative connections.

   *2.2 Analyze the Information:*
   - Objective: Break down the problem logically.
   - Reflection: "Am I considering all factors? Are there any assumptions that need challenging?"
   - Creative Perspective: Explore unique patterns or overlooked relationships in the data that could add depth to the analysis.

   *2.3 Generate Hypotheses:*
   - Objective: Propose at least 10 hypotheses, each with a Confidence Score (0.0 to 1.0) and Creative Score (0.0 to 1.0), reflecting originality, surprise, and utility.
   - Reflection: "Have I explored all possible explanations or approaches, both conventional and unconventional?"
   - Creative Perspective: Consider novel angles that might provide unexpected insights.

   *2.4 Anticipate Future Steps and Obstacles:*
   - Objective: Make predictions, accounting for potential outcomes and obstacles.
   - Reflection: "What challenges might I face? Is my plan flexible for different scenarios?"
   - Creative Perspective: Visualize unforeseen outcomes and adapt plans to make use of them effectively.

   *2.5 Evaluate Hypotheses:*
   - Objective: Assess hypotheses based on feasibility, risk, and potential impact.
   - Evaluation: Refine Confidence and Creative Scores as needed.
   - Reflection: "Am I unbiased in my assessment? Which options fit best with the overall objectives?"
   - Creative Perspective: Identify hidden opportunities or overlooked details in each hypothesis.

   *2.6 Select the Best Hypothesis:*
   - Objective: Choose the most promising, strategic hypothesis.
   - Reflection: "Why does this hypothesis stand out? How does it uniquely address the issue?"
   - Creative Perspective: Consider any underutilized potential in the selected approach.

   *2.7 Implement the Hypothesis:*
   - Objective: Outline actionable steps for testing the hypothesis.
   - Reflection: "Is this plan practical? What resources or preparation are required?"
   - Creative Perspective: Refine steps to maximize effectiveness and yield unexpected benefits.

   *2.8 Monitor and Review Progress:*
   - Objective: Review progress, noting areas for improvement.
   - Reflection: "What’s working well? What could be improved?"
   - Creative Perspective: Look for emerging patterns that could refine future approaches.

   *2.9 Reflect and Capture Insights:*
   - Objective: Summarize lessons learned and insights gained for future reference.
   - Reflection: "What new understanding has emerged from this process?"
   - Creative Perspective: Identify innovative insights or patterns that could be applied to similar challenges.

3. *Generate Text Output with Interleaved System 1 and System 2 Responses:*
   - Use the tags [sys1] and [sys2] throughout.
   - Aim for a lengthier, detailed response. Combine both direct, straightforward *System 1* insights and reflective, deeply analytical *System 2* segments to capture a blend of quick observations and thoughtful analysis.

---

### *Example Input Text:*

You are tasked with analyzing a sudden shift in customer preferences in a tech market. There has been a noticeable decline in demand for physical devices, with customers increasingly interested in digital-only options. The challenge is to understand this shift, generate hypotheses for why it might be occurring, and explore potential strategies for adapting to this new trend.

---

### *Processed Output with System 1 and System 2 Thinking:*

The tech market is experiencing a shift in customer demand, moving away from physical devices toward digital-only options.

[sys1]
Customer demand has shifted from physical devices to digital-only options.
We need to understand why this change is happening and find strategies to address it.
Key factors may include cost, convenience, and technological trends.
[end sys1]

[sys2]
**2.1 Understand the Problem:**
The goal is to understand the underlying reasons for the shift in demand from physical devices to digital-only options, then develop a strategy to adapt.

*Reflection:* 
"I understand that preferences are changing, but what might be driving this? Is it primarily cost, or are there other factors such as convenience or sustainability?"

*Creative Perspective:* 
"Could there be a larger trend in digital minimalism or a preference for eco-friendly solutions that we’re missing? What unseen motivations might explain this shift?"

**2.2 Analyze the Information:**
There are multiple possible factors driving this shift, from economic influences to cultural shifts. It’s essential to isolate each factor and understand its impact.

*Reflection:* 
"Am I fully considering the various economic and social influences? Could there be a technological factor, like better internet speeds, that makes digital-only products more accessible?"

*Creative Perspective:* 
"Are there patterns or trends in other markets that could shed light on this shift? Could this be part of a larger trend toward virtual experiences?"

**2.3 Generate Hypotheses:**
1. Customers prefer digital options due to lower costs. (Confidence: 0.8, Creative: 0.4)
2. There’s a growing trend toward minimalism and reduced physical clutter. (Confidence: 0.7, Creative: 0.7)
3. Digital products offer greater flexibility and ease of use. (Confidence: 0.6, Creative: 0.6)
4. Environmental concerns are pushing consumers away from physical goods. (Confidence: 0.6, Creative: 0.8)
5. Advances in tech make digital-only options more functional. (Confidence: 0.8, Creative: 0.5)
6. Pandemic-era remote work increased demand for digital solutions. (Confidence: 0.7, Creative: 0.6)
7. Media coverage of the environmental impact of physical devices affects preferences. (Confidence: 0.5, Creative: 0.7)
8. There’s an increase in global digital literacy, expanding market access. (Confidence: 0.6, Creative: 0.6)
9. Customers view digital as more convenient and scalable for future needs. (Confidence: 0.7, Creative: 0.5)
10. Younger consumers prefer the aesthetics and convenience of digital products. (Confidence: 0.6, Creative: 0.6)

*Reflection:* 
"Have I considered all possible influences? Are there any surprising factors that could explain this shift?"

*Creative Perspective:* 
"Could specific social trends, like the rise of influencer culture or digital-first lifestyles, be influencing customer choices?"

**2.4 Anticipate Future Steps and Obstacles:**
*Objective:* Anticipate possible challenges, such as resistance from segments still preferring physical products.

*Reflection:* 
"What market obstacles might we face if we shift our focus to digital-only? Are there sub-segments that still prioritize physical products?"

*Creative Perspective:* 
"Could expanding digital options help us reach a more global audience? Are there emerging trends that we could leverage in our strategy?"

[end sys2]

[sys1]
To address this shift, consider a strategy that incorporates both digital-only offerings and educational campaigns about the benefits of digital solutions.
Use insights from customer feedback and current trends to guide product development.
Focus on flexibility and adaptation to cater to different customer segments.
[end sys1]


Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

Abstract

A lithographic process utilizing soft x-rays or ions to achieve high resolution is disclosed. The process is particularly useful and semiconductor processing where high resolution is required to achieve a high density. The process utilizes a mask to selectively expose a photoresist to soft x-rays of flood beams of ions. The mask comprises a thin metallic foil supported by a frame such that the foil is in tension. The frame includes optical alignment keys. A second patterned layer of metal is affixed to the foil to form areas which are non-transparent to the soft x-rays or flood ion beams for delineating the elements of a semiconductor circuit, for example. This permits the mask to be optically aligned using conventionally techniques with high resolution being achieved due to the short wavelength of the x-ray radiation or the ion beams.

Description

The invention relates to semiconductor processing and more specifically to high resolution lithographic processes using soft x-rays or ion beams.

2. Description of the Prior Art

One of the fundamental limitations of high density in semiconductor circuits has been the resolution of the litographic processes. Techniques currently offering the most promise of improving the resolution of lithography is either the so called electron beam writing, processes using flood beams of short wavelength radiation such as x-rays or flood beams of ions. Electron beam writing while providing high resolution is a relatively low production technique due to the time required for the beam writing process. X-ray and flood ion beam lithography has been difficult because the masks are fragile due to the fact that the preferred mask is a thin metal foil such as beryllium. In addition to the fragile nature of such mask, alignment has been difficult due to the fact that a preferred alignment technique is an optical process (i.e., using visible light) and the metallic foil mask is non-transparent in the visible range.

SUMMARY OF THE INVENTION

The invention provides a high resolution lithographic process which utilizes a mask which can be aligned using conventional optical techniques. The mask and short wavelength radiation, such as soft x-rays or ion beams, are used to selectively expose resist layers to form patterned protective layers.

The mask includes a support frame which is transparent to visible light with patterns affixed thereto to form optical alignment keys. A foil, preferably of metal, and transparent to soft x-rays or ions is affixed to the lead frame and held in tension thereby. A patterned layer, preferably of a second metal, is affixed to the foil to render selected areas of the foil nontransparent to soft x-rays or ions. In practicing the disclosed lithographic process, the mask is utilizied to selectively expose resist layers whose chemical structure can be changed in response to exposure to soft x-rays or to ion beams. Following exposure, the resist layers are developed to produce a patterned protective layer to be used in the lithographic process.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross section of the support mask frame and the foil bonded thereto.

FIG. 2 is a drawing illustrating how the flat surface comprising portions of the support frame and the foil is formed.

FIG. 3 is a drawing illustrating the process for bonding the foil to the support frame.

FIG. 4 is a cross section drawing of the support frame and the foil bonded thereto with thin overlying layers of a metal and photoresist.

FIG. 5 is a drawing illustrating the electron beam write-in process utilized to form the mask.

FIG. 6 is a cross section view of the final mask.

FIG. 7 is a drawing illustrating the photolithographic process.

DETAIL DESCRIPTION

FIG. 1 is a cross sectional drawing illustrating the support frame 10 and the thin metallic foil 12, preferably beryllium having a thickness in the order of 25 microns, bonded thereto. In the preferred embodiment, the outer and inner perimeters, 11 and 13, of the support frame may be circular, rectangular or any other convenient shape. Since the support frame 10 is glass, it is not normally transparent to soft x-rays. This limits the useful area for forming masking patterns useful in soft x-ray lithographic techniques to the window formed by the inner perimeter 13 of the support frame 10. Areas of the support frame 10 extending beyond the outer perimeter 15 of the foil 12 are utilized to form keys for aligning the mask using visible light.

A substantially flat common under surface 14 is formed by the surface of the foil 12 and the support frame 10. The foil 12 is bonded to the support frame 10 under conditions which assure that the foil 12 will always be under tension in all directions thus assuring a stable flat surface for the foil 12.

FIG. 2 illustrates the first step in the process for bonding the foil 12 to the support frame 10. A first substantially flat plate 16, of stainless steel for example, is used to support the foil 12. The glass support frame 10 is positioned such that the inner edge 13 of the support frame 10 overlaps the outer edge 15 of the foil 12. A second flat plate 18 is positioned in overlying relationship with the glass support frame 10. Pressure is applied to the two plates 16 and 18 and the whole structure is heated to the softening point of the glass support frame 10. Under these conditions the glass support frame 10 will be deformed such that the bottom edges of the glass support frame 10 become substantially flat with the bottom surface of the foil 12. This produces the substantially flat bottom surface as illustrated in FIG. 1 and previously discussed.

FIG. 3 functionally illustrates the process by which the foil 12 is bonded to the glass member 10. Basically, the foil 12 is electrically conductive because it is preferably a metal such as beryllium. Heating the glass frame 10 to the point where it becomes plastic also causes this member to become slightly electrically conductive. A voltage source 17 of sufficient magnitude is coupled to apply a voltage between the foil 12 and the frame member 10 to cause an electric current to flow between these two members. Bonding time is a function of temperature and current flow. This bonding process is known in the art and fully discussed in U.S. Pat. No. 3,397,278 issued to D. I. Pomerantz. For purposes of illustrating how the glass to metal bond is made, U.S. Pat. No. 3,397,278 is incorporated by reference.

The bonded operation described above will take place normally in a temperature range in from 300° to 800° C. depending upon the glass selected for the support frame 10. Also the glass member 10 will generally have a slightly lower coefficient of expansion than the metallic foil 12. When the bonded operation has been complete and the frame member 10 and the foil 12 are cooled the foil 12 will be under tension assuring that the common surface 14 of the class support frame 14 and the foil 12 will be substantially flat, as discussed above and illustrated in FIG. 1.

After the support frame 10 and the foil 12 have cooled, the bottom surface including the support frame 10 and the foil 12 are coated with a thin layer of gold 20, preferably having a thickness in the range of 1/2 to 1 micron. To facilitate adhesion of the gold layer 20 the bottom surface of the glass support frame 10 and the beryllium layer 12 may be first covered with a very very thin layer of titanium for example. On the surface of the gold layer 20 a thin layer of photoresist 22 is deposited.

Electron beam apparatus functionally illustrated at reference numeral 24 is utilized to selectively expose the photoresist 22. The pattern to be utilized for X-ray photolithographic purposes is confined to an area within the window formed by the inner perimeter 13 of the support frame 10 because the glass support frame will not normally be transparent to the soft x-rays. The regions overlying the edges of the support frame 10 which extend beyond the edge of the foil 12 are utilized to form optical alignment keys which are utilized to align the mask using standard techniques and visible light. The electron beam write-in apparatus 24 can be controlled in a conventional manner to produce the desired pattern for the lithographic processes as well as the alignment keys.

Following electron beam writing, the photoresist layer 22 is developed using conventional processes and the gold layer 20 is etched to produce a pattern for lithographic processes within the window defined by the inner perimeter 13 of the support frame 10 and optical alignment keys in the portions extending beyond the outer perimeter 15 of the foil 12. The finish mask is illustrated in FIG. 6.

The gold images can also be formed using rejection or plating processes. In all cases, the technology for forming the gold images is well known in the art.

The mask illustrated in FIG. 6 is particularly useful in x-ray or flood beam ion lithographic process in of semiconductor wafers. A typical photolithographic process is functionally illustrated in FIG. 7. A semiconductor substrate is coated with a thin layer of photoresist 28 using conventional process in techniques. The mask is then positioned such that the gold pattern layer 20 is in close proximity or actually touching the photoresist layer 28. The alignment keys and the edges of the mask are utilized to properly align the mask with respect to the substrate 26 using well-known optical alignment techniques. Following alignment, a flood beam of soft x-rays or ions is directed to impinge on the upper surface of the mask. The soft x-rays or ions will not penetrate the glass forming in the support frame 10 or the portions of the metallic foil 12 which are overlaid by the patterned gold layer 20. However, in regions where there are openings in the gold patterned layer 20 which are within the inner perimeter 13 of the support frame 10, the soft x-rays or ions will penetrate the foil 12 and impinge upon the photoresist layer 28. The chemical structure of the photoresist layer 28 is modified by the x-rays or the ions. The photoresist layer 28 is then developed and processed to use in conventional processing.

In the above-described process, soft x-rays and ions are utilized because currently available resists are not suitable for use with hard x-rays. It should also be noted that in photolithographic processing of semiconductor wafers that alignment is only critical during the second and subsequent photolithographic processing steps. Thus, the first mask should be designed such that the inner perimeter 13 of the support frame 10 is larger than the active area of the circuit. During the first processing step, alignment patterns must be produced for aligning with the alignment keys. Thus, it is obvious that the mask described above is the type for use with the second and subsequent processing steps because it includes alignment keys in the portions of the support frame 10 which extend beyond the perimeter 15 of the foil 12.

Claims (2)

What we claim is:

1. A mask for use in lithographic processing, comprising in combination:

(a) a glass support frame transparent to visible light and non-transparent to short wave-length radiation;

(b) a beryllium foil non-transparent to visible light and transparent to said short wave-length radiation, said foil being affixed to said support frame such that said support frame extends beyond the perimeter of said foil with said foil and said portions of said support frame which extend beyond the perimeter of said foil joining to form a substantially flat surface; and

(c) a thin patterned layer affixed to said substantially flat surface rendering portions of said beryllium foil and said support frame overlaid by said patterned layer non-transparent to visible light and to radiation within said selected band with portions of said support frame in conjunction with portions of said patterned layer forming a key for aligning said mask permitting said mask to be aligned using visible light.

2. A mask in accordance with claim 1 wherein said beryllium is always in tension, said tension being established by bonding said beryllium foil to said glass from at a temperature above 200° C.