Public

Thread: DRC error Cap

13 Discord messages from ℹ️ - Information/⁉️-questions/threads/drc-error-cap.md.

Category: ℹ️ - Information Parent channel: #⁉️-questions Thread ID: 1444137681712971898

Messages: 13

message-1444137681712971898

2025-11-29T01:27:34.101+00:00 — Mehdi (@enited)

Content

this error does not seem to be solvable. it does not even make sense. if you know the answer, I would appreciate it. It is a DRC error that comes from the cap. apparently it says the bottom plate should be wider than the top ones. and that is what is already there

Attachments

<details> <summary>Attachments data</summary>
[
  {
    "fileName": "image.png",
    "fileSizeBytes": 121610,
    "id": "1444137681956114503",
    "url": "2025-11_media/image-17B9D.png"
  }
]
</details><details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/4f45e115b1159d0a62a4ab23981074e4-7321A.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {}
}
</details>

message-1444138600454291621

2025-11-29T01:31:13.146+00:00 — Tim 'mithro' Ansell (@mithro_)

Content

@Leo Moser (mole99) / @Tim Edwards - Any idea?
<details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/9679bb77da48d47c905b398d98a83780-75B68.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {
    "mentions": [
      {
        "avatarUrl": "2025-11_media/3c7c17f3225f6e56f4dccd83f14383f2-73F83.png",
        "color": null,
        "discriminator": "0000",
        "id": "323371864074485771",
        "isBot": false,
        "name": "mole99",
        "nickname": "Leo Moser (mole99)",
        "roles": [
          {
            "color": null,
            "id": "1423020172595298314",
            "name": "Mod",
            "position": 4
          }
        ]
      },
      {
        "avatarUrl": "2025-11_media/6bcc8e61db497b620550682309ace5d5-D89B4.png",
        "color": null,
        "discriminator": "0000",
        "id": "1365118310701600900",
        "isBot": false,
        "name": "rtimothyedwards_19428",
        "nickname": "Tim Edwards",
        "roles": []
      }
    ]
  }
}
</details>

message-1444138894986579989

2025-11-29T01:32:23.368+00:00 — Hateemx (@hateemx)

Content

more context: that is the cap, between 5 and 6. just being instantiated results in that error

Attachments

<details> <summary>Attachments data</summary>
[
  {
    "fileName": "image.png",
    "fileSizeBytes": 3844,
    "id": "1444138894298710168",
    "url": "2025-11_media/image-3F8F6.png"
  }
]
</details><details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/42977590f2eb075d0eb6b48f02566b7e-3B288.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {}
}
</details>

message-1444152348866773082

2025-11-29T02:25:51.023+00:00 — bailey (@bailey8889)

Content

@Hateemx Here're the relevant rules from the klayout technology. Sorry if the explanation is too long.
```
  mimtm_virtual = fusetop.sized(1.06.um).and(topmin1_metal.interacting(fusetop))
...
  # Rule MIMTM.3: Minimum MiM bottom plate overlap of Top plate.
  logger.info('Executing rule MIMTM.3')
  mimtm3_l1 = fusetop.enclosed(mimtm_virtual, 0.6.um).polygons(0.001.um)
  mimtm3_l2 = fusetop.not_inside(mimtm_virtual)
  mimtm3_l = mimtm3_l1.join(mimtm3_l2)
  mimtm3_l.output('MIMTM.3', 'MIMTM.3 : Minimum MiM bottom plate overlap of Top plate.')
```
When `METAL_LEVEL = 5LM`, `top_min1_metal = metal4`

So `mimtm_virtual` is the intersection of `fusetop` layer grown by 1.06 and `metal4`.
The first part of the rule, `mimtm3_l1` checks that `metal4` encloses `fusetop` by 0.6um.
The second part of the rule `mimtm3_l2` checks for `fusetop` outside of `metal4`.

Note that this rule is checking `metal4` and `fusetop` not `metal4` and `metal5`.
<details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/0-EB806.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {
    "mentions": [
      {
        "avatarUrl": "2025-11_media/42977590f2eb075d0eb6b48f02566b7e-3B288.png",
        "color": null,
        "discriminator": "0000",
        "id": "733031319222878339",
        "isBot": false,
        "name": "hateemx",
        "nickname": "Hateemx",
        "roles": []
      }
    ]
  }
}
</details>

message-1444153581165875210

2025-11-29T02:30:44.826+00:00 — Hateemx (@hateemx)

Content

thanks, the cap is between 5 and 6. and the fusetop is enclosed by 0.6um. I even tried extending metal 5 even more, but no change
<details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/42977590f2eb075d0eb6b48f02566b7e-3B288.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {}
}
</details>

message-1444166320366162040

2025-11-29T03:21:22.088+00:00 — Tim 'mithro' Ansell (@mithro_)

Content

@Hateemx - It's probably a good idea to commit your changes somewhere and share your GDS for other people to look at.
<details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/9679bb77da48d47c905b398d98a83780-75B68.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {
    "mentions": [
      {
        "avatarUrl": "2025-11_media/42977590f2eb075d0eb6b48f02566b7e-3B288.png",
        "color": null,
        "discriminator": "0000",
        "id": "733031319222878339",
        "isBot": false,
        "name": "hateemx",
        "nickname": "Hateemx",
        "roles": []
      }
    ]
  }
}
</details>

message-1444167500966268928

2025-11-29T03:26:03.565+00:00 — Tim Edwards (@rtimothyedwards_19428)

Content

The problem is that "the cap is between 5 and 6" but this process has only 5 metals.
<details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/6bcc8e61db497b620550682309ace5d5-D89B4.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {}
}
</details>

message-1444167719351226511

2025-11-29T03:26:55.632+00:00 — bailey (@bailey8889)

Content

@Hateemx When you say between 5 and 6, do you mean metal5 and metal6? Is this process `6LM` and not `5LM`?
<details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/0-EB806.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {
    "mentions": [
      {
        "avatarUrl": "2025-11_media/42977590f2eb075d0eb6b48f02566b7e-3B288.png",
        "color": null,
        "discriminator": "0000",
        "id": "733031319222878339",
        "isBot": false,
        "name": "hateemx",
        "nickname": "Hateemx",
        "roles": []
      }
    ]
  }
}
</details>

message-1444168327860715602

2025-11-29T03:29:20.712+00:00 — Hateemx (@hateemx)

Content

Yes metal 5 and 6. There is no metal 6 yes I thought it is the same as “top metal” but now I get it. I was just using the 2f0F cap and thought it corresponds to that
<details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/42977590f2eb075d0eb6b48f02566b7e-3B288.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {}
}
</details>

message-1444171140661772329

2025-11-29T03:40:31.336+00:00 — bailey (@bailey8889)

Content

@Hateemx If it's a pcell, there might be an option to specify the lower and/or upper layer.
<details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/0-EB806.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {
    "mentions": [
      {
        "avatarUrl": "2025-11_media/42977590f2eb075d0eb6b48f02566b7e-3B288.png",
        "color": null,
        "discriminator": "0000",
        "id": "733031319222878339",
        "isBot": false,
        "name": "hateemx",
        "nickname": "Hateemx",
        "roles": []
      }
    ]
  }
}
</details>

message-1444180327114473564

2025-11-29T04:17:01.557+00:00 — Hateemx (@hateemx)

Content

The Pcell is called mimcap, without specifying capacitance densities. I can use lower metals but i am mot sure how the density works. So what if it is an M4/M5 cap?

Reactions

<details> <summary>Reactions data</summary>
[
  {
    "count": 1,
    "emoji": {
      "code": "thinking",
      "id": "",
      "imageUrl": "2025-11_media/1f914-15707.svg",
      "isAnimated": false,
      "name": "🤔"
    },
    "users": [
      {
        "avatarUrl": "2025-11_media/0-EB806.png",
        "color": null,
        "discriminator": "0000",
        "id": "738396032295108721",
        "isBot": false,
        "name": "bailey8889",
        "nickname": "bailey"
      }
    ]
  }
]
</details><details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/42977590f2eb075d0eb6b48f02566b7e-3B288.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {}
}
</details>

message-1444236820249317426

2025-11-29T08:01:30.57+00:00 — Leo Moser (mole99) (@mole99)

Content

There's MIM option A and B:

- https://gf180mcu-pdk.readthedocs.io/en/latest/physical_verification/design_manual/drm_10_4_1.html
- https://gf180mcu-pdk.readthedocs.io/en/latest/physical_verification/design_manual/drm_10_4_2.html

Afaik this is the stack up we use: https://gf180mcu-pdk.readthedocs.io/en/latest/analog/layout/inter_specs/inter_specs_3_43.html

So the MIM cap should be on top of Metal4.
<details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/3c7c17f3225f6e56f4dccd83f14383f2-73F83.png",
    "discriminator": "0000",
    "isBot": false,
    "roles": [
      {
        "color": null,
        "id": "1423020172595298314",
        "name": "Mod",
        "position": 4
      }
    ]
  },
  "message": {}
}
</details>

message-1444352997915099259

2025-11-29T15:43:09.484+00:00 — Hateemx (@hateemx)

Content

Thanks everyone!
<details> <summary>Other message metadata</summary>
{
  "author": {
    "avatarUrl": "2025-11_media/42977590f2eb075d0eb6b48f02566b7e-3B288.png",
    "discriminator": "0000",
    "isBot": false
  },
  "message": {}
}
</details>